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2020-05-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix sk_psock reference count leak on receive, from Xiyu Yang. 2) CONFIG_HNS should be invisible, from Geert Uytterhoeven. 3) Don't allow locking route MTUs in ipv6, RFCs actually forbid this, from Maciej Żenczykowski. 4) ipv4 route redirect backoff wasn't actually enforced, from Paolo Abeni. 5) Fix netprio cgroup v2 leak, from Zefan Li. 6) Fix infinite loop on rmmod in conntrack, from Florian Westphal. 7) Fix tcp SO_RCVLOWAT hangs, from Eric Dumazet. 8) Various bpf probe handling fixes, from Daniel Borkmann. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (68 commits) selftests: mptcp: pm: rm the right tmp file dpaa2-eth: properly handle buffer size restrictions bpf: Restrict bpf_trace_printk()'s %s usage and add %pks, %pus specifier bpf: Add bpf_probe_read_{user, kernel}_str() to do_refine_retval_range bpf: Restrict bpf_probe_read{, str}() only to archs where they work MAINTAINERS: Mark networking drivers as Maintained. ipmr: Add lockdep expression to ipmr_for_each_table macro ipmr: Fix RCU list debugging warning drivers: net: hamradio: Fix suspicious RCU usage warning in bpqether.c net: phy: broadcom: fix BCM54XX_SHD_SCR3_TRDDAPD value for BCM54810 tcp: fix error recovery in tcp_zerocopy_receive() MAINTAINERS: Add Jakub to networking drivers. MAINTAINERS: another add of Karsten Graul for S390 networking drivers: ipa: fix typos for ipa_smp2p structure doc pppoe: only process PADT targeted at local interfaces selftests/bpf: Enforce returning 0 for fentry/fexit programs bpf: Enforce returning 0 for fentry/fexit progs net: stmmac: fix num_por initialization security: Fix the default value of secid_to_secctx hook libbpf: Fix register naming in PT_REGS s390 macros ...
2020-05-15bpf: Restrict bpf_trace_printk()'s %s usage and add %pks, %pus specifierDaniel Borkmann
Usage of plain %s conversion specifier in bpf_trace_printk() suffers from the very same issue as bpf_probe_read{,str}() helpers, that is, it is broken on archs with overlapping address ranges. While the helpers have been addressed through work in 6ae08ae3dea2 ("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers"), we need an option for bpf_trace_printk() as well to fix it. Similarly as with the helpers, force users to make an explicit choice by adding %pks and %pus specifier to bpf_trace_printk() which will then pick the corresponding strncpy_from_unsafe*() variant to perform the access under KERNEL_DS or USER_DS. The %pk* (kernel specifier) and %pu* (user specifier) can later also be extended for other objects aside strings that are probed and printed under tracing, and reused out of other facilities like bpf_seq_printf() or BTF based type printing. Existing behavior of %s for current users is still kept working for archs where it is not broken and therefore gated through CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE. For archs not having this property we fall-back to pick probing under KERNEL_DS as a sensible default. Fixes: 8d3b7dce8622 ("bpf: add support for %s specifier to bpf_trace_printk()") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Link: https://lore.kernel.org/bpf/20200515101118.6508-4-daniel@iogearbox.net
2020-05-15bpf: Add bpf_probe_read_{user, kernel}_str() to do_refine_retval_rangeDaniel Borkmann
Given bpf_probe_read{,str}() BPF helpers are now only available under CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE, we need to add the drop-in replacements of bpf_probe_read_{kernel,user}_str() to do_refine_retval_range() as well to avoid hitting the same issue as in 849fa50662fbc ("bpf/verifier: refine retval R0 state for bpf_get_stack helper"). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200515101118.6508-3-daniel@iogearbox.net
2020-05-15bpf: Restrict bpf_probe_read{, str}() only to archs where they workDaniel Borkmann
Given the legacy bpf_probe_read{,str}() BPF helpers are broken on archs with overlapping address ranges, we should really take the next step to disable them from BPF use there. To generally fix the situation, we've recently added new helper variants bpf_probe_read_{user,kernel}() and bpf_probe_read_{user,kernel}_str(). For details on them, see 6ae08ae3dea2 ("bpf: Add probe_read_{user, kernel} and probe_read_{user,kernel}_str helpers"). Given bpf_probe_read{,str}() have been around for ~5 years by now, there are plenty of users at least on x86 still relying on them today, so we cannot remove them entirely w/o breaking the BPF tracing ecosystem. However, their use should be restricted to archs with non-overlapping address ranges where they are working in their current form. Therefore, move this behind a CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE and have x86, arm64, arm select it (other archs supporting it can follow-up on it as well). For the remaining archs, they can workaround easily by relying on the feature probe from bpftool which spills out defines that can be used out of BPF C code to implement the drop-in replacement for old/new kernels via: bpftool feature probe macro Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/bpf/20200515101118.6508-2-daniel@iogearbox.net
2020-05-14bpf: Enforce returning 0 for fentry/fexit progsYonghong Song
Currently, tracing/fentry and tracing/fexit prog return values are not enforced. In trampoline codes, the fentry/fexit prog return values are ignored. Let us enforce it to be 0 to avoid confusion and allows potential future extension. This patch also explicitly added return value checking for tracing/raw_tp, tracing/fmod_ret, and freplace programs such that these program return values can be anything. The purpose are two folds: 1. to make it explicit about return value expectations for these programs in verifier. 2. for tracing prog_type, if a future attach type is added, the default is -ENOTSUPP which will enforce to specify return value ranges explicitly. Fixes: fec56f5890d9 ("bpf: Introduce BPF trampoline") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200514053206.1298415-1-yhs@fb.com
2020-05-14bpf: Fix bug in mmap() implementation for BPF array mapAndrii Nakryiko
mmap() subsystem allows user-space application to memory-map region with initial page offset. This wasn't taken into account in initial implementation of BPF array memory-mapping. This would result in wrong pages, not taking into account requested page shift, being memory-mmaped into user-space. This patch fixes this gap and adds a test for such scenario. Fixes: fc9702273e2e ("bpf: Add mmap() support for BPF_MAP_TYPE_ARRAY") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200512235925.3817805-1-andriin@fb.com
2020-05-14Merge tag 'for-linus-2020-05-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull thread fix from Christian Brauner: "This contains a single fix for all exported legacy fork helpers to block accidental access to clone3() features in the upper 32 bits of their respective flags arguments. I got Cced on a glibc issue where someone reported consistent failures for the legacy clone() syscall on ppc64le when sign extension was performed (since the clone() syscall in glibc exposes the flags argument as an int whereas the kernel uses unsigned long). The legacy clone() syscall is odd in a bunch of ways and here two things interact: - First, legacy clone's flag argument is word-size dependent, i.e. it's an unsigned long whereas most system calls with flag arguments use int or unsigned int. - Second, legacy clone() ignores unknown and deprecated flags. The two of them taken together means that users on 64bit systems can pass garbage for the upper 32bit of the clone() syscall since forever and things would just work fine. The following program compiled on a 64bit kernel prior to v5.7-rc1 will succeed and will fail post v5.7-rc1 with EBADF: int main(int argc, char *argv[]) { pid_t pid; /* Note that legacy clone() has different argument ordering on * different architectures so this won't work everywhere. * * Only set the upper 32 bits. */ pid = syscall(__NR_clone, 0xffffffff00000000 | SIGCHLD, NULL, NULL, NULL, NULL); if (pid < 0) exit(EXIT_FAILURE); if (pid == 0) exit(EXIT_SUCCESS); if (wait(NULL) != pid) exit(EXIT_FAILURE); exit(EXIT_SUCCESS); } Since legacy clone() couldn't be extended this was not a problem so far and nobody really noticed or cared since nothing in the kernel ever bothered to look at the upper 32 bits. But once we introduced clone3() and expanded the flag argument in struct clone_args to 64 bit we opened this can of worms. With the first flag-based extension to clone3() making use of the upper 32 bits of the flag argument we've effectively made it possible for the legacy clone() syscall to reach clone3() only flags on accident. The sign extension scenario is just the odd corner-case that we needed to figure this out. The reason we just realized this now and not already when we introduced CLONE_CLEAR_SIGHAND was that CLONE_INTO_CGROUP assumes that a valid cgroup file descriptor has been given - whereas CLONE_CLEAR_SIGHAND doesn't need to verify anything. It just silently resets the signal handlers to SIG_DFL. So the sign extension (or the user accidently passing garbage for the upper 32 bits) caused the CLONE_INTO_CGROUP bit to be raised and the kernel to error out when it didn't find a valid cgroup file descriptor. Note, I'm also capping kernel_thread()'s flag argument mainly because none of the new features make sense for kernel_thread() and we shouldn't risk them being accidently activated however unlikely. If we wanted to, we could even make kernel_thread() yell when an unknown flag has been set which it doesn't do right now. But it's not worth risking this in a bugfix imho" * tag 'for-linus-2020-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: fork: prevent accidental access to clone3 features
2020-05-14Merge tag 'trace-v5.7-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull more tracing fixes from Steven Rostedt: "Various tracing fixes: - Fix a crash when having function tracing and function stack tracing on the command line. The ftrace trampolines are created as executable and read only. But the stack tracer tries to modify them with text_poke() which expects all kernel text to still be writable at boot. Keep the trampolines writable at boot, and convert them to read-only with the rest of the kernel. - A selftest was triggering in the ring buffer iterator code, that is no longer valid with the update of keeping the ring buffer writable while a iterator is reading. Just bail after three failed attempts to get an event and remove the warning and disabling of the ring buffer. - While modifying the ring buffer code, decided to remove all the unnecessary BUG() calls" * tag 'trace-v5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Remove all BUG() calls ring-buffer: Don't deactivate the ring buffer on failed iterator reads x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up
2020-05-14ring-buffer: Remove all BUG() callsSteven Rostedt (VMware)
There's a lot of checks to make sure the ring buffer is working, and if an anomaly is detected, it safely shuts itself down. But there's a few cases that it will call BUG(), which defeats the point of being safe (it crashes the kernel when an anomaly is found!). There's no reason for them. Switch them all to either WARN_ON_ONCE() (when no ring buffer descriptor is present), or to RB_WARN_ON() (when a ring buffer descriptor is present). Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-14ring-buffer: Don't deactivate the ring buffer on failed iterator readsSteven Rostedt (VMware)
If the function tracer is running and the trace file is read (which uses the ring buffer iterator), the iterator can get in sync with the writes, and caues it to fail to find a page with content it can read three times. This causes a warning and deactivation of the ring buffer code. Looking at the other cases of failure to get an event, it appears that there's a chance that the writer could cause them too. Since the iterator is a "best effort" to read the ring buffer if there's an active writer (the consumer reader is made for this case "see trace_pipe"), if it fails to get an event after three tries, simply give up and return NULL. Don't warn, nor disable the ring buffer on this failure. Link: https://lore.kernel.org/r/20200429090508.GG5770@shao2-debian Reported-by: kernel test robot <lkp@intel.com> Fixes: ff84c50cfb4b ("ring-buffer: Do not die if rb_iter_peek() fails more than thrice") Tested-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-12x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot upSteven Rostedt (VMware)
Booting one of my machines, it triggered the following crash: Kernel/User page tables isolation: enabled ftrace: allocating 36577 entries in 143 pages Starting tracer 'function' BUG: unable to handle page fault for address: ffffffffa000005c #PF: supervisor write access in kernel mode #PF: error_code(0x0003) - permissions violation PGD 2014067 P4D 2014067 PUD 2015063 PMD 7b253067 PTE 7b252061 Oops: 0003 [#1] PREEMPT SMP PTI CPU: 0 PID: 0 Comm: swapper Not tainted 5.4.0-test+ #24 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007 RIP: 0010:text_poke_early+0x4a/0x58 Code: 34 24 48 89 54 24 08 e8 bf 72 0b 00 48 8b 34 24 48 8b 4c 24 08 84 c0 74 0b 48 89 df f3 a4 48 83 c4 10 5b c3 9c 58 fa 48 89 df <f3> a4 50 9d 48 83 c4 10 5b e9 d6 f9 ff ff 0 41 57 49 RSP: 0000:ffffffff82003d38 EFLAGS: 00010046 RAX: 0000000000000046 RBX: ffffffffa000005c RCX: 0000000000000005 RDX: 0000000000000005 RSI: ffffffff825b9a90 RDI: ffffffffa000005c RBP: ffffffffa000005c R08: 0000000000000000 R09: ffffffff8206e6e0 R10: ffff88807b01f4c0 R11: ffffffff8176c106 R12: ffffffff8206e6e0 R13: ffffffff824f2440 R14: 0000000000000000 R15: ffffffff8206eac0 FS: 0000000000000000(0000) GS:ffff88807d400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffa000005c CR3: 0000000002012000 CR4: 00000000000006b0 Call Trace: text_poke_bp+0x27/0x64 ? mutex_lock+0x36/0x5d arch_ftrace_update_trampoline+0x287/0x2d5 ? ftrace_replace_code+0x14b/0x160 ? ftrace_update_ftrace_func+0x65/0x6c __register_ftrace_function+0x6d/0x81 ftrace_startup+0x23/0xc1 register_ftrace_function+0x20/0x37 func_set_flag+0x59/0x77 __set_tracer_option.isra.19+0x20/0x3e trace_set_options+0xd6/0x13e apply_trace_boot_options+0x44/0x6d register_tracer+0x19e/0x1ac early_trace_init+0x21b/0x2c9 start_kernel+0x241/0x518 ? load_ucode_intel_bsp+0x21/0x52 secondary_startup_64+0xa4/0xb0 I was able to trigger it on other machines, when I added to the kernel command line of both "ftrace=function" and "trace_options=func_stack_trace". The cause is the "ftrace=function" would register the function tracer and create a trampoline, and it will set it as executable and read-only. Then the "trace_options=func_stack_trace" would then update the same trampoline to include the stack tracer version of the function tracer. But since the trampoline already exists, it updates it with text_poke_bp(). The problem is that text_poke_bp() called while system_state == SYSTEM_BOOTING, it will simply do a memcpy() and not the page mapping, as it would think that the text is still read-write. But in this case it is not, and we take a fault and crash. Instead, lets keep the ftrace trampolines read-write during boot up, and then when the kernel executable text is set to read-only, the ftrace trampolines get set to read-only as well. Link: https://lkml.kernel.org/r/20200430202147.4dc6e2de@oasis.local.home Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: stable@vger.kernel.org Fixes: 768ae4406a5c ("x86/ftrace: Use text_poke()") Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-12Merge tag 'trace-v5.7-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Fixes to previous fixes. Unfortunately, the last set of fixes introduced some minor bugs: - The bootconfig apply_xbc() leak fix caused the application to return a positive number on success, when it should have returned zero. - The preempt_irq_delay_thread fix to make the creation code wait for the kthread to finish to prevent it from executing after module unload, can now cause the kthread to exit before it even executes (preventing it to run its tests). - The fix to the bootconfig that fixed the initrd to remove the bootconfig from causing the kernel to panic, now prints a warning that the bootconfig is not found, even when bootconfig is not on the command line" * tag 'trace-v5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: bootconfig: Fix to prevent warning message if no bootconfig option tracing: Wait for preempt irq delay thread to execute tools/bootconfig: Fix apply_xbc() to return zero on success
2020-05-11tracing: Wait for preempt irq delay thread to executeSteven Rostedt (VMware)
A bug report was posted that running the preempt irq delay module on a slow machine, and removing it quickly could lead to the thread created by the modlue to execute after the module is removed, and this could cause the kernel to crash. The fix for this was to call kthread_stop() after creating the thread to make sure it finishes before allowing the module to be removed. Now this caused the opposite problem on fast machines. What now happens is the kthread_stop() can cause the kthread never to execute and the test never to run. To fix this, add a completion and wait for the kthread to execute, then wait for it to end. This issue caused the ftracetest selftests to fail on the preemptirq tests. Link: https://lore.kernel.org/r/20200510114210.15d9e4af@oasis.local.home Cc: stable@vger.kernel.org Fixes: d16a8c31077e ("tracing: Wait for preempt irq delay thread to finish") Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-09Stop the ad-hoc games with -Wno-maybe-initializedLinus Torvalds
We have some rather random rules about when we accept the "maybe-initialized" warnings, and when we don't. For example, we consider it unreliable for gcc versions < 4.9, but also if -O3 is enabled, or if optimizing for size. And then various kernel config options disabled it, because they know that they trigger that warning by confusing gcc sufficiently (ie PROFILE_ALL_BRANCHES). And now gcc-10 seems to be introducing a lot of those warnings too, so it falls under the same heading as 4.9 did. At the same time, we have a very straightforward way to _enable_ that warning when wanted: use "W=2" to enable more warnings. So stop playing these ad-hoc games, and just disable that warning by default, with the known and straight-forward "if you want to work on the extra compiler warnings, use W=123". Would it be great to have code that is always so obvious that it never confuses the compiler whether a variable is used initialized or not? Yes, it would. In a perfect world, the compilers would be smarter, and our source code would be simpler. That's currently not the world we live in, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-08umh: fix memory leak on execve failureVincent Minet
If a UMH process created by fork_usermode_blob() fails to execute, a pair of struct file allocated by umh_pipe_setup() will leak. Under normal conditions, the caller (like bpfilter) needs to manage the lifetime of the UMH and its two pipes. But when fork_usermode_blob() fails, the caller doesn't really have a way to know what needs to be done. It seems better to do the cleanup ourselves in this case. Fixes: 449325b52b7a ("umh: introduce fork_usermode_blob() helper") Signed-off-by: Vincent Minet <v.minet@criteo.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-05-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfJakub Kicinski
Daniel Borkmann says: ==================== pull-request: bpf 2020-05-09 The following pull-request contains BPF updates for your *net* tree. We've added 4 non-merge commits during the last 9 day(s) which contain a total of 4 files changed, 11 insertions(+), 6 deletions(-). The main changes are: 1) Fix msg_pop_data() helper incorrectly setting an sge length in some cases as well as fixing bpf_tcp_ingress() wrongly accounting bytes in sg.size, from John Fastabend. 2) Fix to return an -EFAULT error when copy_to_user() of the value fails in map_lookup_and_delete_elem(), from Wei Yongjun. 3) Fix sk_psock refcnt leak in tcp_bpf_recvmsg(), from Xiyu Yang. ==================== Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-05-08Merge tag 'driver-core-5.7-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core fixes from Greg KH: "Here are a number of small driver core fixes for 5.7-rc5 to resolve a bunch of reported issues with the current tree. Biggest here are the reverts and patches from John Stultz to resolve a bunch of deferred probe regressions we have been seeing in 5.7-rc right now. Along with those are some other smaller fixes: - coredump crash fix - devlink fix for when permissive mode was enabled - amba and platform device dma_parms fixes - component error silenced for when deferred probe happens All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: regulator: Revert "Use driver_deferred_probe_timeout for regulator_init_complete_work" driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires driver core: Use dev_warn() instead of dev_WARN() for deferred_probe_timeout warnings driver core: Revert default driver_deferred_probe_timeout value to 0 component: Silence bind error on -EPROBE_DEFER driver core: Fix handling of fw_devlink=permissive coredump: fix crash when umh is disabled amba: Initialize dma_parms for amba devices driver core: platform: Initialize dma_parms for platform devices
2020-05-08Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "14 fixes and one selftest to verify the ipc fixes herein" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm: limit boost_watermark on small zones ubsan: disable UBSAN_ALIGNMENT under COMPILE_TEST mm/vmscan: remove unnecessary argument description of isolate_lru_pages() epoll: atomically remove wait entry on wake up kselftests: introduce new epoll60 testcase for catching lost wakeups percpu: make pcpu_alloc() aware of current gfp context mm/slub: fix incorrect interpretation of s->offset scripts/gdb: repair rb_first() and rb_last() eventpoll: fix missing wakeup for ovflist in ep_poll_callback arch/x86/kvm/svm/sev.c: change flag passed to GUP fast in sev_pin_memory() scripts/decodecode: fix trapping instruction formatting kernel/kcov.c: fix typos in kcov_remote_start documentation mm/page_alloc: fix watchdog soft lockups during set_zone_contiguous() mm, memcg: fix error return value of mem_cgroup_css_alloc() ipc/mqueue.c: change __do_notify() to bypass check_kill_permission()
2020-05-08fork: prevent accidental access to clone3 featuresChristian Brauner
Jan reported an issue where an interaction between sign-extending clone's flag argument on ppc64le and the new CLONE_INTO_CGROUP feature causes clone() to consistently fail with EBADF. The whole story is a little longer. The legacy clone() syscall is odd in a bunch of ways and here two things interact. First, legacy clone's flag argument is word-size dependent, i.e. it's an unsigned long whereas most system calls with flag arguments use int or unsigned int. Second, legacy clone() ignores unknown and deprecated flags. The two of them taken together means that users on 64bit systems can pass garbage for the upper 32bit of the clone() syscall since forever and things would just work fine. Just try this on a 64bit kernel prior to v5.7-rc1 where this will succeed and on v5.7-rc1 where this will fail with EBADF: int main(int argc, char *argv[]) { pid_t pid; /* Note that legacy clone() has different argument ordering on * different architectures so this won't work everywhere. * * Only set the upper 32 bits. */ pid = syscall(__NR_clone, 0xffffffff00000000 | SIGCHLD, NULL, NULL, NULL, NULL); if (pid < 0) exit(EXIT_FAILURE); if (pid == 0) exit(EXIT_SUCCESS); if (wait(NULL) != pid) exit(EXIT_FAILURE); exit(EXIT_SUCCESS); } Since legacy clone() couldn't be extended this was not a problem so far and nobody really noticed or cared since nothing in the kernel ever bothered to look at the upper 32 bits. But once we introduced clone3() and expanded the flag argument in struct clone_args to 64 bit we opened this can of worms. With the first flag-based extension to clone3() making use of the upper 32 bits of the flag argument we've effectively made it possible for the legacy clone() syscall to reach clone3() only flags. The sign extension scenario is just the odd corner-case that we needed to figure this out. The reason we just realized this now and not already when we introduced CLONE_CLEAR_SIGHAND was that CLONE_INTO_CGROUP assumes that a valid cgroup file descriptor has been given. So the sign extension (or the user accidently passing garbage for the upper 32 bits) caused the CLONE_INTO_CGROUP bit to be raised and the kernel to error out when it didn't find a valid cgroup file descriptor. Let's fix this by always capping the upper 32 bits for all codepaths that are not aware of clone3() features. This ensures that we can't reach clone3() only features by accident via legacy clone as with the sign extension case and also that legacy clone() works exactly like before, i.e. ignoring any unknown flags. This solution risks no regressions and is also pretty clean. Fixes: 7f192e3cd316 ("fork: add clone3") Fixes: ef2c41cf38a7 ("clone3: allow spawning processes into cgroups") Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dmitry V. Levin <ldv@altlinux.org> Cc: Andreas Schwab <schwab@linux-m68k.org> Cc: Florian Weimer <fw@deneb.enyo.de> Cc: libc-alpha@sourceware.org Cc: stable@vger.kernel.org # 5.3+ Link: https://sourceware.org/pipermail/libc-alpha/2020-May/113596.html Link: https://lore.kernel.org/r/20200507103214.77218-1-christian.brauner@ubuntu.com
2020-05-07kernel/kcov.c: fix typos in kcov_remote_start documentationMaciej Grochowski
Signed-off-by: Maciej Grochowski <maciej.grochowski@pm.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Link: http://lkml.kernel.org/r/20200420030259.31674-1-maciek.grochowski@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-07Merge tag 'trace-v5.7-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: - Fix bootconfig causing kernels to fail with CONFIG_BLK_DEV_RAM enabled - Fix allocation leaks in bootconfig tool - Fix a double initialization of a variable - Fix API bootconfig usage from kprobe boot time events - Reject NULL location for kprobes - Fix crash caused by preempt delay module not cleaning up kthread correctly - Add vmalloc_sync_mappings() to prevent x86_64 page faults from recursively faulting from tracing page faults - Fix comment in gpu/trace kerneldoc header - Fix documentation of how to create a trace event class - Make the local tracing_snapshot_instance_cond() function static * tag 'trace-v5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tools/bootconfig: Fix resource leak in apply_xbc() tracing: Make tracing_snapshot_instance_cond() static tracing: Fix doc mistakes in trace sample gpu/trace: Minor comment updates for gpu_mem_total tracepoint tracing: Add a vmalloc_sync_mappings() for safe measure tracing: Wait for preempt irq delay thread to finish tracing/kprobes: Reject new event if loc is NULL tracing/boottime: Fix kprobe event API usage tracing/kprobes: Fix a double initialization typo bootconfig: Fix to remove bootconfig data from initrd while boot
2020-05-07tracing: Make tracing_snapshot_instance_cond() staticZou Wei
Fix the following sparse warning: kernel/trace/trace.c:950:6: warning: symbol 'tracing_snapshot_instance_cond' was not declared. Should it be static? Link: http://lkml.kernel.org/r/1587614905-48692-1-git-send-email-zou_wei@huawei.com Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-07tracing: Add a vmalloc_sync_mappings() for safe measureSteven Rostedt (VMware)
x86_64 lazily maps in the vmalloc pages, and the way this works with per_cpu areas can be complex, to say the least. Mappings may happen at boot up, and if nothing synchronizes the page tables, those page mappings may not be synced till they are used. This causes issues for anything that might touch one of those mappings in the path of the page fault handler. When one of those unmapped mappings is touched in the page fault handler, it will cause another page fault, which in turn will cause a page fault, and leave us in a loop of page faults. Commit 763802b53a42 ("x86/mm: split vmalloc_sync_all()") split vmalloc_sync_all() into vmalloc_sync_unmappings() and vmalloc_sync_mappings(), as on system exit, it did not need to do a full sync on x86_64 (although it still needed to be done on x86_32). By chance, the vmalloc_sync_all() would synchronize the page mappings done at boot up and prevent the per cpu area from being a problem for tracing in the page fault handler. But when that synchronization in the exit of a task became a nop, it caused the problem to appear. Link: https://lore.kernel.org/r/20200429054857.66e8e333@oasis.local.home Cc: stable@vger.kernel.org Fixes: 737223fbca3b1 ("tracing: Consolidate buffer allocation code") Reported-by: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> Suggested-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-07tracing: Wait for preempt irq delay thread to finishSteven Rostedt (VMware)
Running on a slower machine, it is possible that the preempt delay kernel thread may still be executing if the module was immediately removed after added, and this can cause the kernel to crash as the kernel thread might be executing after its code has been removed. There's no reason that the caller of the code shouldn't just wait for the delay thread to finish, as the thread can also be created by a trigger in the sysfs code, which also has the same issues. Link: http://lore.kernel.org/r/5EA2B0C8.2080706@cn.fujitsu.com Cc: stable@vger.kernel.org Fixes: 793937236d1ee ("lib: Add module for testing preemptoff/irqsoff latency tracers") Reported-by: Xiao Yang <yangx.jy@cn.fujitsu.com> Reviewed-by: Xiao Yang <yangx.jy@cn.fujitsu.com> Reviewed-by: Joel Fernandes <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-06tracing/kprobes: Reject new event if loc is NULLMasami Hiramatsu
Reject the new event which has NULL location for kprobes. For kprobes, user must specify at least the location. Link: http://lkml.kernel.org/r/158779376597.6082.1411212055469099461.stgit@devnote2 Cc: Tom Zanussi <zanussi@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Fixes: 2a588dd1d5d6 ("tracing: Add kprobe event command generation functions") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-06tracing/boottime: Fix kprobe event API usageMasami Hiramatsu
Fix boottime kprobe events to use API correctly for multiple events. For example, when we set a multiprobe kprobe events in bootconfig like below, ftrace.event.kprobes.myevent { probes = "vfs_read $arg1 $arg2", "vfs_write $arg1 $arg2" } This cause an error; trace_boot: Failed to add probe: p:kprobes/myevent (null) vfs_read $arg1 $arg2 vfs_write $arg1 $arg2 This shows the 1st argument becomes NULL and multiprobes are merged to 1 probe. Link: http://lkml.kernel.org/r/158779375766.6082.201939936008972838.stgit@devnote2 Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Fixes: 29a154810546 ("tracing: Change trace_boot to use kprobe_event interface") Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-06tracing/kprobes: Fix a double initialization typoMasami Hiramatsu
Fix a typo that resulted in an unnecessary double initialization to addr. Link: http://lkml.kernel.org/r/158779374968.6082.2337484008464939919.stgit@devnote2 Cc: Tom Zanussi <zanussi@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Fixes: c7411a1a126f ("tracing/kprobe: Check whether the non-suffixed symbol is notrace") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-04-30bpf: Fix error return code in map_lookup_and_delete_elem()Wei Yongjun
Fix to return negative error code -EFAULT from the copy_to_user() error handling case instead of 0, as done elsewhere in this function. Fixes: bd513cd08f10 ("bpf: add MAP_LOOKUP_AND_DELETE_ELEM syscall") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200430081851.166996-1-weiyongjun1@huawei.com
2020-04-28coredump: fix crash when umh is disabledLuis Chamberlain
Commit 64e90a8acb859 ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()") added the optiont to disable all call_usermodehelper() calls by setting STATIC_USERMODEHELPER_PATH to an empty string. When this is done, and crashdump is triggered, it will crash on null pointer dereference, since we make assumptions over what call_usermodehelper_exec() did. This has been reported by Sergey when one triggers a a coredump with the following configuration: ``` CONFIG_STATIC_USERMODEHELPER=y CONFIG_STATIC_USERMODEHELPER_PATH="" kernel.core_pattern = |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e ``` The way disabling the umh was designed was that call_usermodehelper_exec() would just return early, without an error. But coredump assumes certain variables are set up for us when this happens, and calls ile_start_write(cprm.file) with a NULL file. [ 2.819676] BUG: kernel NULL pointer dereference, address: 0000000000000020 [ 2.819859] #PF: supervisor read access in kernel mode [ 2.820035] #PF: error_code(0x0000) - not-present page [ 2.820188] PGD 0 P4D 0 [ 2.820305] Oops: 0000 [#1] SMP PTI [ 2.820436] CPU: 2 PID: 89 Comm: a Not tainted 5.7.0-rc1+ #7 [ 2.820680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014 [ 2.821150] RIP: 0010:do_coredump+0xd80/0x1060 [ 2.821385] Code: e8 95 11 ed ff 48 c7 c6 cc a7 b4 81 48 8d bd 28 ff ff ff 89 c2 e8 70 f1 ff ff 41 89 c2 85 c0 0f 84 72 f7 ff ff e9 b4 fe ff ff <48> 8b 57 20 0f b7 02 66 25 00 f0 66 3d 00 8 0 0f 84 9c 01 00 00 44 [ 2.822014] RSP: 0000:ffffc9000029bcb8 EFLAGS: 00010246 [ 2.822339] RAX: 0000000000000000 RBX: ffff88803f860000 RCX: 000000000000000a [ 2.822746] RDX: 0000000000000009 RSI: 0000000000000282 RDI: 0000000000000000 [ 2.823141] RBP: ffffc9000029bde8 R08: 0000000000000000 R09: ffffc9000029bc00 [ 2.823508] R10: 0000000000000001 R11: ffff88803dec90be R12: ffffffff81c39da0 [ 2.823902] R13: ffff88803de84400 R14: 0000000000000000 R15: 0000000000000000 [ 2.824285] FS: 00007fee08183540(0000) GS:ffff88803e480000(0000) knlGS:0000000000000000 [ 2.824767] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.825111] CR2: 0000000000000020 CR3: 000000003f856005 CR4: 0000000000060ea0 [ 2.825479] Call Trace: [ 2.825790] get_signal+0x11e/0x720 [ 2.826087] do_signal+0x1d/0x670 [ 2.826361] ? force_sig_info_to_task+0xc1/0xf0 [ 2.826691] ? force_sig_fault+0x3c/0x40 [ 2.826996] ? do_trap+0xc9/0x100 [ 2.827179] exit_to_usermode_loop+0x49/0x90 [ 2.827359] prepare_exit_to_usermode+0x77/0xb0 [ 2.827559] ? invalid_op+0xa/0x30 [ 2.827747] ret_from_intr+0x20/0x20 [ 2.827921] RIP: 0033:0x55e2c76d2129 [ 2.828107] Code: 2d ff ff ff e8 68 ff ff ff 5d c6 05 18 2f 00 00 01 c3 0f 1f 80 00 00 00 00 c3 0f 1f 80 00 00 00 00 e9 7b ff ff ff 55 48 89 e5 <0f> 0b b8 00 00 00 00 5d c3 66 2e 0f 1f 84 0 0 00 00 00 00 0f 1f 40 [ 2.828603] RSP: 002b:00007fffeba5e080 EFLAGS: 00010246 [ 2.828801] RAX: 000055e2c76d2125 RBX: 0000000000000000 RCX: 00007fee0817c718 [ 2.829034] RDX: 00007fffeba5e188 RSI: 00007fffeba5e178 RDI: 0000000000000001 [ 2.829257] RBP: 00007fffeba5e080 R08: 0000000000000000 R09: 00007fee08193c00 [ 2.829482] R10: 0000000000000009 R11: 0000000000000000 R12: 000055e2c76d2040 [ 2.829727] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 2.829964] CR2: 0000000000000020 [ 2.830149] ---[ end trace ceed83d8c68a1bf1 ]--- ``` Cc: <stable@vger.kernel.org> # v4.11+ Fixes: 64e90a8acb85 ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199795 Reported-by: Tony Vroon <chainsaw@gentoo.org> Reported-by: Sergey Kvachonok <ravenexp@gmail.com> Tested-by: Sergei Trofimovich <slyfox@gentoo.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20200416162859.26518-1-mcgrof@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-27PM: hibernate: Freeze kernel threads in software_resume()Dexuan Cui
Currently the kernel threads are not frozen in software_resume(), so between dpm_suspend_start(PMSG_QUIESCE) and resume_target_kernel(), system_freezable_power_efficient_wq can still try to submit SCSI commands and this can cause a panic since the low level SCSI driver (e.g. hv_storvsc) has quiesced the SCSI adapter and can not accept any SCSI commands: https://lkml.org/lkml/2020/4/10/47 At first I posted a fix (https://lkml.org/lkml/2020/4/21/1318) trying to resolve the issue from hv_storvsc, but with the help of Bart Van Assche, I realized it's better to fix software_resume(), since this looks like a generic issue, not only pertaining to SCSI. Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-04-25Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull pid leak fix from Eric Biederman: "Oleg noticed that put_pid(thread_pid) was not getting called when proc was not compiled in. Let's get that fixed before 5.7 is released and causes problems for anyone" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Put thread_pid in release_task not proc_flush_pid
2020-04-25Merge tag 'sched-urgent-2020-04-25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Misc fixes: - an uclamp accounting fix - three frequency invariance fixes and a readability improvement" * tag 'sched-urgent-2020-04-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Fix reset-on-fork from RT with uclamp x86, sched: Move check for CPU type to caller function x86, sched: Don't enable static key when starting secondary CPUs x86, sched: Account for CPUs with less than 4 cores in freq. invariance x86, sched: Bail out of frequency invariance if base frequency is unknown
2020-04-25Merge tag 'perf-urgent-2020-04-25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Two changes: - fix exit event records - extend x86 PMU driver enumeration to add Intel Jasper Lake CPU support" * tag 'perf-urgent-2020-04-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: fix parent pid/tid in task exit events perf/x86/cstate: Add Jasper Lake CPU support
2020-04-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix memory leak in netfilter flowtable, from Roi Dayan. 2) Ref-count leaks in netrom and tipc, from Xiyu Yang. 3) Fix warning when mptcp socket is never accepted before close, from Florian Westphal. 4) Missed locking in ovs_ct_exit(), from Tonghao Zhang. 5) Fix large delays during PTP synchornization in cxgb4, from Rahul Lakkireddy. 6) team_mode_get() can hang, from Taehee Yoo. 7) Need to use kvzalloc() when allocating fw tracer in mlx5 driver, from Niklas Schnelle. 8) Fix handling of bpf XADD on BTF memory, from Jann Horn. 9) Fix BPF_STX/BPF_B encoding in x86 bpf jit, from Luke Nelson. 10) Missing queue memory release in iwlwifi pcie code, from Johannes Berg. 11) Fix NULL deref in macvlan device event, from Taehee Yoo. 12) Initialize lan87xx phy correctly, from Yuiko Oshino. 13) Fix looping between VRF and XFRM lookups, from David Ahern. 14) etf packet scheduler assumes all sockets are full sockets, which is not necessarily true. From Eric Dumazet. 15) Fix mptcp data_fin handling in RX path, from Paolo Abeni. 16) fib_select_default() needs to handle nexthop objects, from David Ahern. 17) Use GFP_ATOMIC under spinlock in mac80211_hwsim, from Wei Yongjun. 18) vxlan and geneve use wrong nlattr array, from Sabrina Dubroca. 19) Correct rx/tx stats in bcmgenet driver, from Doug Berger. 20) BPF_LDX zero-extension is encoded improperly in x86_32 bpf jit, fix from Luke Nelson. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (100 commits) selftests/bpf: Fix a couple of broken test_btf cases tools/runqslower: Ensure own vmlinux.h is picked up first bpf: Make bpf_link_fops static bpftool: Respect the -d option in struct_ops cmd selftests/bpf: Add test for freplace program with expected_attach_type bpf: Propagate expected_attach_type when verifying freplace programs bpf: Fix leak in LINK_UPDATE and enforce empty old_prog_fd bpf, x86_32: Fix logic error in BPF_LDX zero-extension bpf, x86_32: Fix clobbering of dst for BPF_JSET bpf, x86_32: Fix incorrect encoding in BPF_LDX zero-extension bpf: Fix reStructuredText markup net: systemport: suppress warnings on failed Rx SKB allocations net: bcmgenet: suppress warnings on failed Rx SKB allocations macsec: avoid to set wrong mtu mac80211: sta_info: Add lockdep condition for RCU list usage mac80211: populate debugfs only after cfg80211 init net: bcmgenet: correct per TX/RX ring statistics net: meth: remove spurious copyright text net: phy: bcm84881: clear settings on link down chcr: Fix CPU hard lockup ...
2020-04-24bpf: Make bpf_link_fops staticZou Wei
Fix the following sparse warning: kernel/bpf/syscall.c:2289:30: warning: symbol 'bpf_link_fops' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/1587609160-117806-1-git-send-email-zou_wei@huawei.com
2020-04-24bpf: Propagate expected_attach_type when verifying freplace programsToke Høiland-Jørgensen
For some program types, the verifier relies on the expected_attach_type of the program being verified in the verification process. However, for freplace programs, the attach type was not propagated along with the verifier ops, so the expected_attach_type would always be zero for freplace programs. This in turn caused the verifier to sometimes make the wrong call for freplace programs. For all existing uses of expected_attach_type for this purpose, the result of this was only false negatives (i.e., freplace functions would be rejected by the verifier even though they were valid programs for the target they were replacing). However, should a false positive be introduced, this can lead to out-of-bounds accesses and/or crashes. The fix introduced in this patch is to propagate the expected_attach_type to the freplace program during verification, and reset it after that is done. Fixes: be8704ff07d2 ("bpf: Introduce dynamic program extensions") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/158773526726.293902.13257293296560360508.stgit@toke.dk
2020-04-24bpf: Fix leak in LINK_UPDATE and enforce empty old_prog_fdAndrii Nakryiko
Fix bug of not putting bpf_link in LINK_UPDATE command. Also enforce zeroed old_prog_fd if no BPF_F_REPLACE flag is specified. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200424052045.4002963-1-andriin@fb.com
2020-04-24proc: Put thread_pid in release_task not proc_flush_pidEric W. Biederman
Oleg pointed out that in the unlikely event the kernel is compiled with CONFIG_PROC_FS unset that release_task will now leak the pid. Move the put_pid out of proc_flush_pid into release_task to fix this and to guarantee I don't make that mistake again. When possible it makes sense to keep get and put in the same function so it can easily been seen how they pair up. Fixes: 7bc3e6e55acf ("proc: Use a list of inodes to flush from proc") Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-04-24Merge tag 'trace-v5.7-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "A few tracing fixes: - Two fixes for memory leaks detected by kmemleak - Removal of some dead code - A few local functions turned static" * tag 'trace-v5.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Convert local functions in tracing_map.c to static tracing: Remove DECLARE_TRACE_NOARGS ftrace: Fix memory leak caused by not freeing entry in unregister_ftrace_direct() tracing: Fix memory leaks in trace_events_hist.c
2020-04-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull SIGCHLD fix from Eric Biederman: "Christof Meerwald reported that do_notify_parent has not been successfully populating si_pid and si_uid for multi-threaded processes. This is the one-liner fix. Strictly speaking a one-liner plus comment" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: signal: Avoid corrupting si_pid and si_uid in do_notify_parent
2020-04-22tracing: Convert local functions in tracing_map.c to staticJason Yan
Fix the following sparse warning: kernel/trace/tracing_map.c:286:6: warning: symbol 'tracing_map_array_clear' was not declared. Should it be static? kernel/trace/tracing_map.c:297:6: warning: symbol 'tracing_map_array_free' was not declared. Should it be static? kernel/trace/tracing_map.c:319:26: warning: symbol 'tracing_map_array_alloc' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20200410073312.38855-1-yanaijie@huawei.com Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-04-22ftrace: Fix memory leak caused by not freeing entry in ↵Steven Rostedt (VMware)
unregister_ftrace_direct() kmemleak reported the following: unreferenced object 0xffff90d47127a920 (size 32): comm "modprobe", pid 1766, jiffies 4294792031 (age 162.568s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 22 01 00 00 00 00 ad de ........"....... 00 78 12 a7 ff ff ff ff 00 00 b6 c0 ff ff ff ff .x.............. backtrace: [<00000000bb79e72e>] register_ftrace_direct+0xcb/0x3a0 [<00000000295e4f79>] do_one_initcall+0x72/0x340 [<00000000873ead18>] do_init_module+0x5a/0x220 [<00000000974d9de5>] load_module+0x2235/0x2550 [<0000000059c3d6ce>] __do_sys_finit_module+0xc0/0x120 [<000000005a8611b4>] do_syscall_64+0x60/0x230 [<00000000a0cdc49e>] entry_SYSCALL_64_after_hwframe+0x49/0xb3 The entry used to save the direct descriptor needs to be freed when unregistering. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-04-22tracing: Fix memory leaks in trace_events_hist.cVamshi K Sthambamkadi
kmemleak report 1: [<9092c50b>] kmem_cache_alloc_trace+0x138/0x270 [<05a2c9ed>] create_field_var+0xcf/0x180 [<528a2d68>] action_create+0xe2/0xc80 [<63f50b61>] event_hist_trigger_func+0x15b5/0x1920 [<28ea5d3d>] trigger_process_regex+0x7b/0xc0 [<3138e86f>] event_trigger_write+0x4d/0xb0 [<ffd66c19>] __vfs_write+0x30/0x200 [<4f424a0d>] vfs_write+0x96/0x1b0 [<da59a290>] ksys_write+0x53/0xc0 [<3717101a>] __ia32_sys_write+0x15/0x20 [<c5f23497>] do_fast_syscall_32+0x70/0x250 [<46e2629c>] entry_SYSENTER_32+0xaf/0x102 This is because save_vars[] of struct hist_trigger_data are not destroyed kmemleak report 2: [<9092c50b>] kmem_cache_alloc_trace+0x138/0x270 [<6e5e97c5>] create_var+0x3c/0x110 [<de82f1b9>] create_field_var+0xaf/0x180 [<528a2d68>] action_create+0xe2/0xc80 [<63f50b61>] event_hist_trigger_func+0x15b5/0x1920 [<28ea5d3d>] trigger_process_regex+0x7b/0xc0 [<3138e86f>] event_trigger_write+0x4d/0xb0 [<ffd66c19>] __vfs_write+0x30/0x200 [<4f424a0d>] vfs_write+0x96/0x1b0 [<da59a290>] ksys_write+0x53/0xc0 [<3717101a>] __ia32_sys_write+0x15/0x20 [<c5f23497>] do_fast_syscall_32+0x70/0x250 [<46e2629c>] entry_SYSENTER_32+0xaf/0x102 struct hist_field allocated through create_var() do not initialize "ref" field to 1. The code in __destroy_hist_field() does not destroy object if "ref" is initialized to zero, the condition if (--hist_field->ref > 1) always passes since unsigned int wraps. kmemleak report 3: [<f8666fcc>] __kmalloc_track_caller+0x139/0x2b0 [<bb7f80a5>] kstrdup+0x27/0x50 [<39d70006>] init_var_ref+0x58/0xd0 [<8ca76370>] create_var_ref+0x89/0xe0 [<f045fc39>] action_create+0x38f/0xc80 [<7c146821>] event_hist_trigger_func+0x15b5/0x1920 [<07de3f61>] trigger_process_regex+0x7b/0xc0 [<e87daf8f>] event_trigger_write+0x4d/0xb0 [<19bf1512>] __vfs_write+0x30/0x200 [<64ce4d27>] vfs_write+0x96/0x1b0 [<a6f34170>] ksys_write+0x53/0xc0 [<7d4230cd>] __ia32_sys_write+0x15/0x20 [<8eadca00>] do_fast_syscall_32+0x70/0x250 [<235cf985>] entry_SYSENTER_32+0xaf/0x102 hist_fields (system & event_name) are not freed Link: http://lkml.kernel.org/r/20200422061503.GA5151@cosmos Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-04-22perf/core: fix parent pid/tid in task exit eventsIan Rogers
Current logic yields the child task as the parent. Before: $ perf record bash -c "perf list > /dev/null" $ perf script -D |grep 'FORK\|EXIT' 4387036190981094 0x5a70 [0x30]: PERF_RECORD_FORK(10472:10472):(10470:10470) 4387036606207580 0xf050 [0x30]: PERF_RECORD_EXIT(10472:10472):(10472:10472) 4387036607103839 0x17150 [0x30]: PERF_RECORD_EXIT(10470:10470):(10470:10470) ^ Note the repeated values here -------------------/ After: 383281514043 0x9d8 [0x30]: PERF_RECORD_FORK(2268:2268):(2266:2266) 383442003996 0x2180 [0x30]: PERF_RECORD_EXIT(2268:2268):(2266:2266) 383451297778 0xb70 [0x30]: PERF_RECORD_EXIT(2266:2266):(2265:2265) Fixes: 94d5d1b2d891 ("perf_counter: Report the cloning task as parent on perf_counter_fork()") Reported-by: KP Singh <kpsingh@google.com> Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200417182842.12522-1-irogers@google.com
2020-04-22sched/core: Fix reset-on-fork from RT with uclampQuentin Perret
uclamp_fork() resets the uclamp values to their default when the reset-on-fork flag is set. It also checks whether the task has a RT policy, and sets its uclamp.min to 1024 accordingly. However, during reset-on-fork, the task's policy is lowered to SCHED_NORMAL right after, hence leading to an erroneous uclamp.min setting for the new task if it was forked from RT. Fix this by removing the unnecessary check on rt_task() in uclamp_fork() as this doesn't make sense if the reset-on-fork flag is set. Fixes: 1a00d999971c ("sched/uclamp: Set default clamps for RT tasks") Reported-by: Chitti Babu Theegala <ctheegal@codeaurora.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Patrick Bellasi <patrick.bellasi@matbug.net> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lkml.kernel.org/r/20200416085956.217587-1-qperret@google.com
2020-04-21signal: Avoid corrupting si_pid and si_uid in do_notify_parentEric W. Biederman
Christof Meerwald <cmeerw@cmeerw.org> writes: > Hi, > > this is probably related to commit > 7a0cf094944e2540758b7f957eb6846d5126f535 (signal: Correct namespace > fixups of si_pid and si_uid). > > With a 5.6.5 kernel I am seeing SIGCHLD signals that don't include a > properly set si_pid field - this seems to happen for multi-threaded > child processes. > > A simple test program (based on the sample from the signalfd man page): > > #include <sys/signalfd.h> > #include <signal.h> > #include <unistd.h> > #include <spawn.h> > #include <stdlib.h> > #include <stdio.h> > > #define handle_error(msg) \ > do { perror(msg); exit(EXIT_FAILURE); } while (0) > > int main(int argc, char *argv[]) > { > sigset_t mask; > int sfd; > struct signalfd_siginfo fdsi; > ssize_t s; > > sigemptyset(&mask); > sigaddset(&mask, SIGCHLD); > > if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1) > handle_error("sigprocmask"); > > pid_t chldpid; > char *chldargv[] = { "./sfdclient", NULL }; > posix_spawn(&chldpid, "./sfdclient", NULL, NULL, chldargv, NULL); > > sfd = signalfd(-1, &mask, 0); > if (sfd == -1) > handle_error("signalfd"); > > for (;;) { > s = read(sfd, &fdsi, sizeof(struct signalfd_siginfo)); > if (s != sizeof(struct signalfd_siginfo)) > handle_error("read"); > > if (fdsi.ssi_signo == SIGCHLD) { > printf("Got SIGCHLD %d %d %d %d\n", > fdsi.ssi_status, fdsi.ssi_code, > fdsi.ssi_uid, fdsi.ssi_pid); > return 0; > } else { > printf("Read unexpected signal\n"); > } > } > } > > > and a multi-threaded client to test with: > > #include <unistd.h> > #include <pthread.h> > > void *f(void *arg) > { > sleep(100); > } > > int main() > { > pthread_t t[8]; > > for (int i = 0; i != 8; ++i) > { > pthread_create(&t[i], NULL, f, NULL); > } > } > > I tried to do a bit of debugging and what seems to be happening is > that > > /* From an ancestor pid namespace? */ > if (!task_pid_nr_ns(current, task_active_pid_ns(t))) { > > fails inside task_pid_nr_ns because the check for "pid_alive" fails. > > This code seems to be called from do_notify_parent and there we > actually have "tsk != current" (I am assuming both are threads of the > current process?) I instrumented the code with a warning and received the following backtrace: > WARNING: CPU: 0 PID: 777 at kernel/pid.c:501 __task_pid_nr_ns.cold.6+0xc/0x15 > Modules linked in: > CPU: 0 PID: 777 Comm: sfdclient Not tainted 5.7.0-rc1userns+ #2924 > Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > RIP: 0010:__task_pid_nr_ns.cold.6+0xc/0x15 > Code: ff 66 90 48 83 ec 08 89 7c 24 04 48 8d 7e 08 48 8d 74 24 04 e8 9a b6 44 00 48 83 c4 08 c3 48 c7 c7 59 9f ac 82 e8 c2 c4 04 00 <0f> 0b e9 3fd > RSP: 0018:ffffc9000042fbf8 EFLAGS: 00010046 > RAX: 000000000000000c RBX: 0000000000000000 RCX: ffffc9000042faf4 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff81193d29 > RBP: ffffc9000042fc18 R08: 0000000000000000 R09: 0000000000000001 > R10: 000000100f938416 R11: 0000000000000309 R12: ffff8880b941c140 > R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880b941c140 > FS: 0000000000000000(0000) GS:ffff8880bca00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f2e8c0a32e0 CR3: 0000000002e10000 CR4: 00000000000006f0 > Call Trace: > send_signal+0x1c8/0x310 > do_notify_parent+0x50f/0x550 > release_task.part.21+0x4fd/0x620 > do_exit+0x6f6/0xaf0 > do_group_exit+0x42/0xb0 > get_signal+0x13b/0xbb0 > do_signal+0x2b/0x670 > ? __audit_syscall_exit+0x24d/0x2b0 > ? rcu_read_lock_sched_held+0x4d/0x60 > ? kfree+0x24c/0x2b0 > do_syscall_64+0x176/0x640 > ? trace_hardirqs_off_thunk+0x1a/0x1c > entry_SYSCALL_64_after_hwframe+0x49/0xb3 The immediate problem is as Christof noticed that "pid_alive(current) == false". This happens because do_notify_parent is called from the last thread to exit in a process after that thread has been reaped. The bigger issue is that do_notify_parent can be called from any process that manages to wait on a thread of a multi-threaded process from wait_task_zombie. So any logic based upon current for do_notify_parent is just nonsense, as current can be pretty much anything. So change do_notify_parent to call __send_signal directly. Inspecting the code it appears this problem has existed since the pid namespace support started handling this case in 2.6.30. This fix only backports to 7a0cf094944e ("signal: Correct namespace fixups of si_pid and si_uid") where the problem logic was moved out of __send_signal and into send_signal. Cc: stable@vger.kernel.org Fixes: 6588c1e3ff01 ("signals: SI_USER: Masquerade si_pid when crossing pid ns boundary") Ref: 921cf9f63089 ("signals: protect cinit from unblocked SIG_DFL signals") Link: https://lore.kernel.org/lkml/20200419201336.GI22017@edge.cmeerw.net/ Reported-by: Christof Meerwald <cmeerw@cmeerw.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-04-20bpf: Fix handling of XADD on BTF memoryJann Horn
check_xadd() can cause check_ptr_to_btf_access() to be executed with atype==BPF_READ and value_regno==-1 (meaning "just check whether the access is okay, don't tell me what type it will result in"). Handle that case properly and skip writing type information, instead of indexing into the registers at index -1 and writing into out-of-bounds memory. Note that at least at the moment, you can't actually write through a BTF pointer, so check_xadd() will reject the program after calling check_ptr_to_btf_access with atype==BPF_WRITE; but that's after the verifier has already corrupted memory. This patch assumes that BTF pointers are not available in unprivileged programs. Fixes: 9e15db66136a ("bpf: Implement accurate raw_tp context access via BTF") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200417000007.10734-2-jannh@google.com
2020-04-20bpf: Forbid XADD on spilled pointers for unprivileged usersJann Horn
When check_xadd() verifies an XADD operation on a pointer to a stack slot containing a spilled pointer, check_stack_read() verifies that the read, which is part of XADD, is valid. However, since the placeholder value -1 is passed as `value_regno`, check_stack_read() can only return a binary decision and can't return the type of the value that was read. The intent here is to verify whether the value read from the stack slot may be used as a SCALAR_VALUE; but since check_stack_read() doesn't check the type, and the type information is lost when check_stack_read() returns, this is not enforced, and a malicious user can abuse XADD to leak spilled kernel pointers. Fix it by letting check_stack_read() verify that the value is usable as a SCALAR_VALUE if no type information is passed to the caller. To be able to use __is_pointer_value() in check_stack_read(), move it up. Fix up the expected unprivileged error message for a BPF selftest that, until now, assumed that unprivileged users can use XADD on stack-spilled pointers. This also gives us a test for the behavior introduced in this patch for free. In theory, this could also be fixed by forbidding XADD on stack spills entirely, since XADD is a locked operation (for operations on memory with concurrency) and there can't be any concurrency on the BPF stack; but Alexei has said that he wants to keep XADD on stack slots working to avoid changes to the test suite [1]. The following BPF program demonstrates how to leak a BPF map pointer as an unprivileged user using this bug: // r7 = map_pointer BPF_LD_MAP_FD(BPF_REG_7, small_map), // r8 = launder(map_pointer) BPF_STX_MEM(BPF_DW, BPF_REG_FP, BPF_REG_7, -8), BPF_MOV64_IMM(BPF_REG_1, 0), ((struct bpf_insn) { .code = BPF_STX | BPF_DW | BPF_XADD, .dst_reg = BPF_REG_FP, .src_reg = BPF_REG_1, .off = -8 }), BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_FP, -8), // store r8 into map BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_7), BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP), BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -4), BPF_ST_MEM(BPF_W, BPF_REG_ARG2, 0, 0), BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), BPF_EXIT_INSN(), BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_8, 0), BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN() [1] https://lore.kernel.org/bpf/20200416211116.qxqcza5vo2ddnkdq@ast-mbp.dhcp.thefacebook.com/ Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200417000007.10734-1-jannh@google.com
2020-04-20cpumap: Avoid warning when CONFIG_DEBUG_PER_CPU_MAPS is enabledToke Høiland-Jørgensen
When the kernel is built with CONFIG_DEBUG_PER_CPU_MAPS, the cpumap code can trigger a spurious warning if CONFIG_CPUMASK_OFFSTACK is also set. This happens because in this configuration, NR_CPUS can be larger than nr_cpumask_bits, so the initial check in cpu_map_alloc() is not sufficient to guard against hitting the warning in cpumask_check(). Fix this by explicitly checking the supplied key against the nr_cpumask_bits variable before calling cpu_possible(). Fixes: 6710e1126934 ("bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP") Reported-by: Xiumei Mu <xmu@redhat.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Xiumei Mu <xmu@redhat.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200416083120.453718-1-toke@redhat.com
2020-04-20audit: check the length of userspace generated audit recordsPaul Moore
Commit 756125289285 ("audit: always check the netlink payload length in audit_receive_msg()") fixed a number of missing message length checks, but forgot to check the length of userspace generated audit records. The good news is that you need CAP_AUDIT_WRITE to submit userspace audit records, which is generally only given to trusted processes, so the impact should be limited. Cc: stable@vger.kernel.org Fixes: 756125289285 ("audit: always check the netlink payload length in audit_receive_msg()") Reported-by: syzbot+49e69b4d71a420ceda3e@syzkaller.appspotmail.com Signed-off-by: Paul Moore <paul@paul-moore.com>