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2022-03-07Merge tag 'x86_bugs_for_v5.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 spectre fixes from Borislav Petkov: - Mitigate Spectre v2-type Branch History Buffer attacks on machines which support eIBRS, i.e., the hardware-assisted speculation restriction after it has been shown that such machines are vulnerable even with the hardware mitigation. - Do not use the default LFENCE-based Spectre v2 mitigation on AMD as it is insufficient to mitigate such attacks. Instead, switch to retpolines on all AMD by default. - Update the docs and add some warnings for the obviously vulnerable cmdline configurations. * tag 'x86_bugs_for_v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/speculation: Warn about eIBRS + LFENCE + Unprivileged eBPF + SMT x86/speculation: Warn about Spectre v2 LFENCE mitigation x86/speculation: Update link to AMD speculation whitepaper x86/speculation: Use generic retpoline by default on AMD x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting Documentation/hw-vuln: Update spectre doc x86/speculation: Add eIBRS + Retpoline options x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE
2022-03-07swiotlb: rework "fix info leak with DMA_FROM_DEVICE"Halil Pasic
Unfortunately, we ended up merging an old version of the patch "fix info leak with DMA_FROM_DEVICE" instead of merging the latest one. Christoph (the swiotlb maintainer), he asked me to create an incremental fix (after I have pointed this out the mix up, and asked him for guidance). So here we go. The main differences between what we got and what was agreed are: * swiotlb_sync_single_for_device is also required to do an extra bounce * We decided not to introduce DMA_ATTR_OVERWRITE until we have exploiters * The implantation of DMA_ATTR_OVERWRITE is flawed: DMA_ATTR_OVERWRITE must take precedence over DMA_ATTR_SKIP_CPU_SYNC Thus this patch removes DMA_ATTR_OVERWRITE, and makes swiotlb_sync_single_for_device() bounce unconditionally (that is, also when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale data from the swiotlb buffer. Let me note, that if the size used with dma_sync_* API is less than the size used with dma_[un]map_*, under certain circumstances we may still end up with swiotlb not being transparent. In that sense, this is no perfect fix either. To get this bullet proof, we would have to bounce the entire mapping/bounce buffer. For that we would have to figure out the starting address, and the size of the mapping in swiotlb_sync_single_for_device(). While this does seem possible, there seems to be no firm consensus on how things are supposed to work. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Fixes: ddbd89deb7d3 ("swiotlb: fix info leak with DMA_FROM_DEVICE") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-06Merge tag 'trace-v5.17-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: - Fix sorting on old "cpu" value in histograms - Fix return value of __setup() boot parameter handlers * tag 'trace-v5.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix return value of __setup handlers tracing/histogram: Fix sorting on old "cpu" value
2022-03-05Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "8 patches. Subsystems affected by this patch series: mm (hugetlb, pagemap, and userfaultfd), memfd, selftests, and kconfig" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: configs/debug: set CONFIG_DEBUG_INFO=y properly proc: fix documentation and description of pagemap kselftest/vm: fix tests build with old libc memfd: fix F_SEAL_WRITE after shmem huge page allocated mm: fix use-after-free when anon vma name is used after vma is freed mm: prevent vm_area_struct::anon_name refcount saturation mm: refactor vm_area_struct::anon_vma_name usage code selftests/vm: cleanup hugetlb file after mremap test
2022-03-05configs/debug: set CONFIG_DEBUG_INFO=y properlyQian Cai
CONFIG_DEBUG_INFO can't be set by user directly, so set CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y instead. Otherwise, we end up with no debuginfo in vmlinux which is a big no-no for kernel debugging. Link: https://lkml.kernel.org/r/20220301202920.18488-1-quic_qiancai@quicinc.com Signed-off-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-05mm: refactor vm_area_struct::anon_vma_name usage codeSuren Baghdasaryan
Avoid mixing strings and their anon_vma_name referenced pointers by using struct anon_vma_name whenever possible. This simplifies the code and allows easier sharing of anon_vma_name structures when they represent the same name. [surenb@google.com: fix comment] Link: https://lkml.kernel.org/r/20220223153613.835563-1-surenb@google.com Link: https://lkml.kernel.org/r/20220224231834.1481408-1-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Colin Cross <ccross@google.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Alexey Gladkov <legion@kernel.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Chris Hyser <chris.hyser@oracle.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Xiaofeng Cao <caoxiaofeng@yulong.com> Cc: David Hildenbrand <david@redhat.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-04Merge tag 'block-5.17-2022-03-04' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fix from Jens Axboe: "Just a small UAF fix for blktrace" * tag 'block-5.17-2022-03-04' of git://git.kernel.dk/linux-block: blktrace: fix use after free for struct blk_trace
2022-03-04tracing: Fix return value of __setup handlersRandy Dunlap
__setup() handlers should generally return 1 to indicate that the boot options have been handled. Using invalid option values causes the entire kernel boot option string to be reported as Unknown and added to init's environment strings, polluting it. Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6 kprobe_event=p,syscall_any,$arg1 trace_options=quiet trace_clock=jiffies", will be passed to user space. Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc6 kprobe_event=p,syscall_any,$arg1 trace_options=quiet trace_clock=jiffies Return 1 from the __setup() handlers so that init's environment is not polluted with kernel boot options. Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Link: https://lkml.kernel.org/r/20220303031744.32356-1-rdunlap@infradead.org Cc: stable@vger.kernel.org Fixes: 7bcfaf54f591 ("tracing: Add trace_options kernel command line parameter") Fixes: e1e232ca6b8f ("tracing: Add trace_clock=<clock> kernel parameter") Fixes: 970988e19eb0 ("tracing/kprobe: Add kprobe_event= boot parameter") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-02Merge branch 'ucount-rlimit-fixes-for-v5.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ucounts fix from Eric Biederman: "Etienne Dechamps recently found a regression caused by enforcing RLIMIT_NPROC for root where the rlimit was not previously enforced. Michal Koutný had previously pointed out the inconsistency in enforcing the RLIMIT_NPROC that had been on the root owned process after the root user creates a user namespace. Which makes the fix for the regression simply removing the inconsistency" * 'ucount-rlimit-fixes-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ucounts: Fix systemd LimitNPROC with private users regression
2022-03-01tracing/histogram: Fix sorting on old "cpu" valueSteven Rostedt (Google)
When trying to add a histogram against an event with the "cpu" field, it was impossible due to "cpu" being a keyword to key off of the running CPU. So to fix this, it was changed to "common_cpu" to match the other generic fields (like "common_pid"). But since some scripts used "cpu" for keying off of the CPU (for events that did not have "cpu" as a field, which is most of them), a backward compatibility trick was added such that if "cpu" was used as a key, and the event did not have "cpu" as a field name, then it would fallback and switch over to "common_cpu". This fix has a couple of subtle bugs. One was that when switching over to "common_cpu", it did not change the field name, it just set a flag. But the code still found a "cpu" field. The "cpu" field is used for filtering and is returned when the event does not have a "cpu" field. This was found by: # cd /sys/kernel/tracing # echo hist:key=cpu,pid:sort=cpu > events/sched/sched_wakeup/trigger # cat events/sched/sched_wakeup/hist Which showed the histogram unsorted: { cpu: 19, pid: 1175 } hitcount: 1 { cpu: 6, pid: 239 } hitcount: 2 { cpu: 23, pid: 1186 } hitcount: 14 { cpu: 12, pid: 249 } hitcount: 2 { cpu: 3, pid: 994 } hitcount: 5 Instead of hard coding the "cpu" checks, take advantage of the fact that trace_event_field_field() returns a special field for "cpu" and "CPU" if the event does not have "cpu" as a field. This special field has the "filter_type" of "FILTER_CPU". Check that to test if the returned field is of the CPU type instead of doing the string compare. Also, fix the sorting bug by testing for the hist_field flag of HIST_FIELD_FL_CPU when setting up the sort routine. Otherwise it will use the special CPU field to know what compare routine to use, and since that special field does not have a size, it returns tracing_map_cmp_none. Cc: stable@vger.kernel.org Fixes: 1e3bac71c505 ("tracing/histogram: Rename "cpu" to "common_cpu"") Reported-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-28blktrace: fix use after free for struct blk_traceYu Kuai
When tracing the whole disk, 'dropped' and 'msg' will be created under 'q->debugfs_dir' and 'bt->dir' is NULL, thus blk_trace_free() won't remove those files. What's worse, the following UAF can be triggered because of accessing stale 'dropped' and 'msg': ================================================================== BUG: KASAN: use-after-free in blk_dropped_read+0x89/0x100 Read of size 4 at addr ffff88816912f3d8 by task blktrace/1188 CPU: 27 PID: 1188 Comm: blktrace Not tainted 5.17.0-rc4-next-20220217+ #469 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-4 Call Trace: <TASK> dump_stack_lvl+0x34/0x44 print_address_description.constprop.0.cold+0xab/0x381 ? blk_dropped_read+0x89/0x100 ? blk_dropped_read+0x89/0x100 kasan_report.cold+0x83/0xdf ? blk_dropped_read+0x89/0x100 kasan_check_range+0x140/0x1b0 blk_dropped_read+0x89/0x100 ? blk_create_buf_file_callback+0x20/0x20 ? kmem_cache_free+0xa1/0x500 ? do_sys_openat2+0x258/0x460 full_proxy_read+0x8f/0xc0 vfs_read+0xc6/0x260 ksys_read+0xb9/0x150 ? vfs_write+0x3d0/0x3d0 ? fpregs_assert_state_consistent+0x55/0x60 ? exit_to_user_mode_prepare+0x39/0x1e0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fbc080d92fd Code: ce 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 1 RSP: 002b:00007fbb95ff9cb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fbb95ff9dc0 RCX: 00007fbc080d92fd RDX: 0000000000000100 RSI: 00007fbb95ff9cc0 RDI: 0000000000000045 RBP: 0000000000000045 R08: 0000000000406299 R09: 00000000fffffffd R10: 000000000153afa0 R11: 0000000000000293 R12: 00007fbb780008c0 R13: 00007fbb78000938 R14: 0000000000608b30 R15: 00007fbb780029c8 </TASK> Allocated by task 1050: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x81/0xa0 do_blk_trace_setup+0xcb/0x410 __blk_trace_setup+0xac/0x130 blk_trace_ioctl+0xe9/0x1c0 blkdev_ioctl+0xf1/0x390 __x64_sys_ioctl+0xa5/0xe0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 1050: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0x103/0x180 kfree+0x9a/0x4c0 __blk_trace_remove+0x53/0x70 blk_trace_ioctl+0x199/0x1c0 blkdev_common_ioctl+0x5e9/0xb30 blkdev_ioctl+0x1a5/0x390 __x64_sys_ioctl+0xa5/0xe0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88816912f380 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 88 bytes inside of 96-byte region [ffff88816912f380, ffff88816912f3e0) The buggy address belongs to the page: page:000000009a1b4e7c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0f flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff) raw: 0017ffffc0000200 ffffea00044f1100 dead000000000002 ffff88810004c780 raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88816912f280: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88816912f300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff88816912f380: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88816912f400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88816912f480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ================================================================== Fixes: c0ea57608b69 ("blktrace: remove debugfs file dentries from struct blk_trace") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20220228034354.4047385-1-yukuai3@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-27Merge tag 'dma-mapping-5.17-1' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds
Pull dma-mapping fix from Christoph Hellwig: - fix a swiotlb info leak (Halil Pasic) * tag 'dma-mapping-5.17-1' of git://git.infradead.org/users/hch/dma-mapping: swiotlb: fix info leak with DMA_FROM_DEVICE
2022-02-26Merge tag 'trace-v5.17-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: - rtla (Real-Time Linux Analysis tool): - fix typo in man page - Update API -e to -E before it is released - Error message fix and memory leak fix - Partially uninline trace event soft disable to shrink text - Fix function graph start up test - Have triggers affect the trace instance they are in and not top level - Have osnoise sleep in the units it says it uses - Remove unused ftrace stub function - Remove event probe redundant info from event in the buffer - Fix group ownership setting in tracefs - Ensure trace buffer is minimum size to prevent crashes * tag 'trace-v5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: rtla/osnoise: Fix error message when failing to enable trace instance rtla/osnoise: Free params at the exit rtla/hist: Make -E the short version of --entries tracing: Fix selftest config check for function graph start up test tracefs: Set the group ownership in apply_options() not parse_options() tracing/osnoise: Make osnoise_main to sleep for microseconds ftrace: Remove unused ftrace_startup_enable() stub tracing: Ensure trace buffer is at least 4096 bytes large tracing: Uninline trace_trigger_soft_disabled() partly eprobes: Remove redundant event type information tracing: Have traceon and traceoff trigger honor the instance tracing: Dump stacktrace trigger to the corresponding instance rtla: Fix systme -> system typo on man page
2022-02-25tracing: Fix selftest config check for function graph start up testChristophe Leroy
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is required to test direct tramp. Link: https://lkml.kernel.org/r/bdc7e594e13b0891c1d61bc8d56c94b1890eaed7.1640017960.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25tracing/osnoise: Make osnoise_main to sleep for microsecondsDaniel Bristot de Oliveira
osnoise's runtime and period are in the microseconds scale, but it is currently sleeping in the millisecond's scale. This behavior roots in the usage of hwlat as the skeleton for osnoise. Make osnoise to sleep in the microseconds scale. Also, move the sleep to a specialized function. Link: https://lkml.kernel.org/r/302aa6c7bdf2d131719b22901905e9da122a11b2.1645197336.git.bristot@kernel.org Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25ftrace: Remove unused ftrace_startup_enable() stubNathan Chancellor
When building with clang + CONFIG_DYNAMIC_FTRACE=n + W=1, there is a warning: kernel/trace/ftrace.c:7194:20: error: unused function 'ftrace_startup_enable' [-Werror,-Wunused-function] static inline void ftrace_startup_enable(int command) { } ^ 1 error generated. Clang warns on instances of static inline functions in .c files with W=1 after commit 6863f5643dd7 ("kbuild: allow Clang to find unused static inline functions for W=1 build"). The ftrace_startup_enable() stub has been unused since commit e1effa0144a1 ("ftrace: Annotate the ops operation on update"), where its use outside of the CONFIG_DYNAMIC_TRACE section was replaced by ftrace_startup_all(). Remove it to resolve the warning. Link: https://lkml.kernel.org/r/20220214192847.488166-1-nathan@kernel.org Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25tracing: Ensure trace buffer is at least 4096 bytes largeSven Schnelle
Booting the kernel with 'trace_buf_size=1' give a warning at boot during the ftrace selftests: [ 0.892809] Running postponed tracer tests: [ 0.892893] Testing tracer function: [ 0.901899] Callback from call_rcu_tasks_trace() invoked. [ 0.983829] Callback from call_rcu_tasks_rude() invoked. [ 1.072003] .. bad ring buffer .. corrupted trace buffer .. [ 1.091944] Callback from call_rcu_tasks() invoked. [ 1.097695] PASSED [ 1.097701] Testing dynamic ftrace: .. filter failed count=0 ..FAILED! [ 1.353474] ------------[ cut here ]------------ [ 1.353478] WARNING: CPU: 0 PID: 1 at kernel/trace/trace.c:1951 run_tracer_selftest+0x13c/0x1b0 Therefore enforce a minimum of 4096 bytes to make the selftest pass. Link: https://lkml.kernel.org/r/20220214134456.1751749-1-svens@linux.ibm.com Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25tracing: Uninline trace_trigger_soft_disabled() partlyChristophe Leroy
On a powerpc32 build with CONFIG_CC_OPTIMISE_FOR_SIZE, the inline keyword is not honored and trace_trigger_soft_disabled() appears approx 50 times in vmlinux. Adding -Winline to the build, the following message appears: ./include/linux/trace_events.h:712:1: error: inlining failed in call to 'trace_trigger_soft_disabled': call is unlikely and code size would grow [-Werror=inline] That function is rather big for an inlined function: c003df60 <trace_trigger_soft_disabled>: c003df60: 94 21 ff f0 stwu r1,-16(r1) c003df64: 7c 08 02 a6 mflr r0 c003df68: 90 01 00 14 stw r0,20(r1) c003df6c: bf c1 00 08 stmw r30,8(r1) c003df70: 83 e3 00 24 lwz r31,36(r3) c003df74: 73 e9 01 00 andi. r9,r31,256 c003df78: 41 82 00 10 beq c003df88 <trace_trigger_soft_disabled+0x28> c003df7c: 38 60 00 00 li r3,0 c003df80: 39 61 00 10 addi r11,r1,16 c003df84: 4b fd 60 ac b c0014030 <_rest32gpr_30_x> c003df88: 73 e9 00 80 andi. r9,r31,128 c003df8c: 7c 7e 1b 78 mr r30,r3 c003df90: 41 a2 00 14 beq c003dfa4 <trace_trigger_soft_disabled+0x44> c003df94: 38 c0 00 00 li r6,0 c003df98: 38 a0 00 00 li r5,0 c003df9c: 38 80 00 00 li r4,0 c003dfa0: 48 05 c5 f1 bl c009a590 <event_triggers_call> c003dfa4: 73 e9 00 40 andi. r9,r31,64 c003dfa8: 40 82 00 28 bne c003dfd0 <trace_trigger_soft_disabled+0x70> c003dfac: 73 ff 02 00 andi. r31,r31,512 c003dfb0: 41 82 ff cc beq c003df7c <trace_trigger_soft_disabled+0x1c> c003dfb4: 80 01 00 14 lwz r0,20(r1) c003dfb8: 83 e1 00 0c lwz r31,12(r1) c003dfbc: 7f c3 f3 78 mr r3,r30 c003dfc0: 83 c1 00 08 lwz r30,8(r1) c003dfc4: 7c 08 03 a6 mtlr r0 c003dfc8: 38 21 00 10 addi r1,r1,16 c003dfcc: 48 05 6f 6c b c0094f38 <trace_event_ignore_this_pid> c003dfd0: 38 60 00 01 li r3,1 c003dfd4: 4b ff ff ac b c003df80 <trace_trigger_soft_disabled+0x20> However it is located in a hot path so inlining it is important. But forcing inlining of the entire function by using __always_inline leads to increasing the text size by approx 20 kbytes. Instead, split the fonction in two parts, one part with the likely fast path, flagged __always_inline, and a second part out of line. With this change, on a powerpc32 with CONFIG_CC_OPTIMISE_FOR_SIZE vmlinux text increases by only 1,4 kbytes, which is partly compensated by a decrease of vmlinux data by 7 kbytes. On ppc64_defconfig which has CONFIG_CC_OPTIMISE_FOR_SPEED, this change reduces vmlinux text by more than 30 kbytes. Link: https://lkml.kernel.org/r/69ce0986a52d026d381d612801d978aa4f977460.1644563295.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25eprobes: Remove redundant event type informationSteven Rostedt (Google)
Currently, the event probes save the type of the event they are attached to when recording the event. For example: # echo 'e:switch sched/sched_switch prev_state=$prev_state prev_prio=$prev_prio next_pid=$next_pid next_prio=$next_prio' > dynamic_events # cat events/eprobes/switch/format name: switch ID: 1717 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:unsigned int __probe_type; offset:8; size:4; signed:0; field:u64 prev_state; offset:12; size:8; signed:0; field:u64 prev_prio; offset:20; size:8; signed:0; field:u64 next_pid; offset:28; size:8; signed:0; field:u64 next_prio; offset:36; size:8; signed:0; print fmt: "(%u) prev_state=0x%Lx prev_prio=0x%Lx next_pid=0x%Lx next_prio=0x%Lx", REC->__probe_type, REC->prev_state, REC->prev_prio, REC->next_pid, REC->next_prio The __probe_type adds 4 bytes to every event. One of the reasons for creating eprobes is to limit what is traced in an event to be able to limit what is written into the ring buffer. Having this redundant 4 bytes to every event takes away from this. The event that is recorded can be retrieved from the event probe itself, that is available when the trace is happening. For user space tools, it could simply read the dynamic_event file to find the event they are for. So there is really no reason to write this information into the ring buffer for every event. Link: https://lkml.kernel.org/r/20220218190057.2f5a19a8@gandalf.local.home Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Joel Fernandes <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25tracing: Have traceon and traceoff trigger honor the instanceSteven Rostedt (Google)
If a trigger is set on an event to disable or enable tracing within an instance, then tracing should be disabled or enabled in the instance and not at the top level, which is confusing to users. Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home Cc: stable@vger.kernel.org Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables") Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25ucounts: Fix systemd LimitNPROC with private users regressionEric W. Biederman
Long story short recursively enforcing RLIMIT_NPROC when it is not enforced on the process that creates a new user namespace, causes currently working code to fail. There is no reason to enforce RLIMIT_NPROC recursively when we don't enforce it normally so update the code to detect this case. I would like to simply use capable(CAP_SYS_RESOURCE) to detect when RLIMIT_NPROC is not enforced upon the caller. Unfortunately because RLIMIT_NPROC is charged and checked for enforcement based upon the real uid, using capable() which is euid based is inconsistent with reality. Come as close as possible to testing for capable(CAP_SYS_RESOURCE) by testing for when the real uid would match the conditions when CAP_SYS_RESOURCE would be present if the real uid was the effective uid. Reported-by: Etienne Dechamps <etienne@edechamps.fr> Link: https://bugzilla.kernel.org/show_bug.cgi?id=215596 Link: https://lkml.kernel.org/r/e9589141-cfeb-90cd-2d0e-83a62787239a@edechamps.fr Link: https://lkml.kernel.org/r/87sfs8jmpz.fsf_-_@email.froward.int.ebiederm.org Cc: stable@vger.kernel.org Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-24tracing: Dump stacktrace trigger to the corresponding instanceDaniel Bristot de Oliveira
The stacktrace event trigger is not dumping the stacktrace to the instance where it was enabled, but to the global "instance." Use the private_data, pointing to the trigger file, to figure out the corresponding trace instance, and use it in the trigger action, like snapshot_trigger does. Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org Cc: stable@vger.kernel.org Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables") Reviewed-by: Tom Zanussi <zanussi@kernel.org> Tested-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-24Merge tag 'net-5.17-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from bpf and netfilter. Current release - regressions: - bpf: fix crash due to out of bounds access into reg2btf_ids - mvpp2: always set port pcs ops, avoid null-deref - eth: marvell: fix driver load from initrd - eth: intel: revert "Fix reset bw limit when DCB enabled with 1 TC" Current release - new code bugs: - mptcp: fix race in overlapping signal events Previous releases - regressions: - xen-netback: revert hotplug-status changes causing devices to not be configured - dsa: - avoid call to __dev_set_promiscuity() while rtnl_mutex isn't held - fix panic when removing unoffloaded port from bridge - dsa: microchip: fix bridging with more than two member ports Previous releases - always broken: - bpf: - fix crash due to incorrect copy_map_value when both spin lock and timer are present in a single value - fix a bpf_timer initialization issue with clang - do not try bpf_msg_push_data with len 0 - add schedule points in batch ops - nf_tables: - unregister flowtable hooks on netns exit - correct flow offload action array size - fix a couple of memory leaks - vsock: don't check owner in vhost_vsock_stop() while releasing - gso: do not skip outer ip header in case of ipip and net_failover - smc: use a mutex for locking "struct smc_pnettable" - openvswitch: fix setting ipv6 fields causing hw csum failure - mptcp: fix race in incoming ADD_ADDR option processing - sysfs: add check for netdevice being present to speed_show - sched: act_ct: fix flow table lookup after ct clear or switching zones - eth: intel: fixes for SR-IOV forwarding offloads - eth: broadcom: fixes for selftests and error recovery - eth: mellanox: flow steering and SR-IOV forwarding fixes Misc: - make __pskb_pull_tail() & pskb_carve_frag_list() drop_monitor friends not report freed skbs as drops - force inlining of checksum functions in net/checksum.h" * tag 'net-5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (85 commits) net: mv643xx_eth: process retval from of_get_mac_address ping: remove pr_err from ping_lookup Revert "i40e: Fix reset bw limit when DCB enabled with 1 TC" openvswitch: Fix setting ipv6 fields causing hw csum failure ipv6: prevent a possible race condition with lifetimes net/smc: Use a mutex for locking "struct smc_pnettable" bnx2x: fix driver load from initrd Revert "xen-netback: Check for hotplug-status existence before watching" Revert "xen-netback: remove 'hotplug-status' once it has served its purpose" net/mlx5e: Fix VF min/max rate parameters interchange mistake net/mlx5e: Add missing increment of count net/mlx5e: MPLSoUDP decap, fix check for unsupported matches net/mlx5e: Fix MPLSoUDP encap to use MPLS action information net/mlx5e: Add feature check for set fec counters net/mlx5e: TC, Skip redundant ct clear actions net/mlx5e: TC, Reject rules with forward and drop actions net/mlx5e: TC, Reject rules with drop and modify hdr action net/mlx5e: kTLS, Use CHECKSUM_UNNECESSARY for device-offloaded packets net/mlx5e: Fix wrong return value on ioctl EEPROM query failure net/mlx5: Fix possible deadlock on rule deletion ...
2022-02-22Merge branch 'for-5.17-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - Fix for a subtle bug in the recent release_agent permission check update - Fix for a long-standing race condition between cpuset and cpu hotplug - Comment updates * 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: Fix kernel-doc cgroup-v1: Correct privileges check in release_agent writes cgroup: clarify cgroup_css_set_fork() cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug
2022-02-22cpuset: Fix kernel-docJiapeng Chong
Fix the following W=1 kernel warnings: kernel/cgroup/cpuset.c:3718: warning: expecting prototype for cpuset_memory_pressure_bump(). Prototype was for __cpuset_memory_pressure_bump() instead. kernel/cgroup/cpuset.c:3568: warning: expecting prototype for cpuset_node_allowed(). Prototype was for __cpuset_node_allowed() instead. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-22cgroup-v1: Correct privileges check in release_agent writesMichal Koutný
The idea is to check: a) the owning user_ns of cgroup_ns, b) capabilities in init_user_ns. The commit 24f600856418 ("cgroup-v1: Require capabilities to set release_agent") got this wrong in the write handler of release_agent since it checked user_ns of the opener (may be different from the owning user_ns of cgroup_ns). Secondly, to avoid possibly confused deputy, the capability of the opener must be checked. Fixes: 24f600856418 ("cgroup-v1: Require capabilities to set release_agent") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/stable/20220216121142.GB30035@blackbody.suse.cz/ Signed-off-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Masami Ichikawa(CIP) <masami.ichikawa@cybertrust.co.jp> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-22cgroup: clarify cgroup_css_set_fork()Christian Brauner
With recent fixes for the permission checking when moving a task into a cgroup using a file descriptor to a cgroup's cgroup.procs file and calling write() it seems a good idea to clarify CLONE_INTO_CGROUP permission checking with a comment. Cc: Tejun Heo <tj@kernel.org> Cc: <cgroups@vger.kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-21x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation ↵Josh Poimboeuf
reporting With unprivileged eBPF enabled, eIBRS (without retpoline) is vulnerable to Spectre v2 BHB-based attacks. When both are enabled, print a warning message and report it in the 'spectre_v2' sysfs vulnerabilities file. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2022-02-20Merge tag 'locking_urgent_for_v5.17_rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fix from Borislav Petkov: "Fix a NULL ptr dereference when dumping lockdep chains through /proc/lockdep_chains" * tag 'locking_urgent_for_v5.17_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Correct lock_classes index mapping
2022-02-20Merge tag 'sched_urgent_for_v5.17_rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Borislav Petkov: "Fix task exposure order when forking tasks" * tag 'sched_urgent_for_v5.17_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix yet more sched_fork() races
2022-02-20Merge tag 'pidfd.v5.17-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull pidfd fix from Christian Brauner: "This fixes a problem reported by lockdep when installing a pidfd via fd_install() with siglock and the tasklisk write lock held in copy_process() when calling clone()/clone3() with CLONE_PIDFD. Originally a pidfd was created prior to holding any of these locks but this required a call to ksys_close(). So quite some time ago in 6fd2fe494b17 ("copy_process(): don't use ksys_close() on cleanups") we switched to a get_unused_fd_flags() + fd_install() model. As part of that we moved fd_install() as late as possible. This was done for two main reasons. First, because we needed to ensure that we call fd_install() past the point of no return as once that's called the fd is live in the task's file table. Second, because we tried to ensure that the fd is visible in /proc/<pid>/fd/<pidfd> right when the task is visible. This fix moves the fd_install() to an even later point which means that a task will be visible in proc while the pidfd isn't yet under /proc/<pid>/fd/<pidfd>. While this is a user visible change it's very unlikely that this will have any impact. Nobody should be relying on that and if they do we need to come up with something better but again, it's doubtful this is relevant" * tag 'pidfd.v5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: copy_process(): Move fd_install() out of sighand->siglock critical section
2022-02-20Merge branch 'ucount-rlimit-fixes-for-v5.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ucounts fixes from Eric Biederman: "Michal Koutný recently found some bugs in the enforcement of RLIMIT_NPROC in the recent ucount rlimit implementation. In this set of patches I have developed a very conservative approach changing only what is necessary to fix the bugs that I can see clearly. Cleanups and anything that is making the code more consistent can follow after we have the code working as it has historically. The problem is not so much inconsistencies (although those exist) but that it is very difficult to figure out what the code should be doing in the case of RLIMIT_NPROC. All other rlimits are only enforced where the resource is acquired (allocated). RLIMIT_NPROC by necessity needs to be enforced in an additional location, and our current implementation stumbled it's way into that implementation" * 'ucount-rlimit-fixes-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ucounts: Handle wrapping in is_ucounts_overlimit ucounts: Move RLIMIT_NPROC handling after set_user ucounts: Base set_cred_ucounts changes on the real user ucounts: Enforce RLIMIT_NPROC not RLIMIT_NPROC+1 rlimit: Fix RLIMIT_NPROC enforcement failure caused by capability calls in set_user
2022-02-19sched: Fix yet more sched_fork() racesPeter Zijlstra
Where commit 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group") fixed a fork race vs cgroup, it opened up a race vs syscalls by not placing the task on the runqueue before it gets exposed through the pidhash. Commit 13765de8148f ("sched/fair: Fix fault in reweight_entity") is trying to fix a single instance of this, instead fix the whole class of issues, effectively reverting this commit. Fixes: 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Tadeusz Struk <tadeusz.struk@linaro.org> Tested-by: Zhang Qiao <zhangqiao22@huawei.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lkml.kernel.org/r/YgoeCbwj5mbCR0qA@hirez.programming.kicks-ass.net
2022-02-17Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfJakub Kicinski
Alexei Starovoitov says: ==================== pull-request: bpf 2022-02-17 We've added 8 non-merge commits during the last 7 day(s) which contain a total of 8 files changed, 119 insertions(+), 15 deletions(-). The main changes are: 1) Add schedule points in map batch ops, from Eric. 2) Fix bpf_msg_push_data with len 0, from Felix. 3) Fix crash due to incorrect copy_map_value, from Kumar. 4) Fix crash due to out of bounds access into reg2btf_ids, from Kumar. 5) Fix a bpf_timer initialization issue with clang, from Yonghong. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Add schedule points in batch ops bpf: Fix crash due to out of bounds access into reg2btf_ids. selftests: bpf: Check bpf_msg_push_data return value bpf: Fix a bpf_timer initialization issue bpf: Emit bpf_timer in vmlinux BTF selftests/bpf: Add test for bpf_timer overwriting crash bpf: Fix crash due to incorrect copy_map_value bpf: Do not try bpf_msg_push_data with len 0 ==================== Link: https://lore.kernel.org/r/20220217190000.37925-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-17bpf: Add schedule points in batch opsEric Dumazet
syzbot reported various soft lockups caused by bpf batch operations. INFO: task kworker/1:1:27 blocked for more than 140 seconds. INFO: task hung in rcu_barrier Nothing prevents batch ops to process huge amount of data, we need to add schedule points in them. Note that maybe_wait_bpf_programs(map) calls from generic_map_delete_batch() can be factorized by moving the call after the loop. This will be done later in -next tree once we get this fix merged, unless there is strong opinion doing this optimization sooner. Fixes: aa2e93b8e58e ("bpf: Add generic support for update and delete batch ops") Fixes: cb4d03ab499d ("bpf: Add generic support for lookup batch op") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Stanislav Fomichev <sdf@google.com> Acked-by: Brian Vazquez <brianvv@google.com> Link: https://lore.kernel.org/bpf/20220217181902.808742-1-eric.dumazet@gmail.com
2022-02-17ucounts: Handle wrapping in is_ucounts_overlimitEric W. Biederman
While examining is_ucounts_overlimit and reading the various messages I realized that is_ucounts_overlimit fails to deal with counts that may have wrapped. Being wrapped should be a transitory state for counts and they should never be wrapped for long, but it can happen so handle it. Cc: stable@vger.kernel.org Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Link: https://lkml.kernel.org/r/20220216155832.680775-5-ebiederm@xmission.com Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-17ucounts: Move RLIMIT_NPROC handling after set_userEric W. Biederman
During set*id() which cred->ucounts to charge the the current process to is not known until after set_cred_ucounts. So move the RLIMIT_NPROC checking into a new helper flag_nproc_exceeded and call flag_nproc_exceeded after set_cred_ucounts. This is very much an arbitrary subset of the places where we currently change the RLIMIT_NPROC accounting, designed to preserve the existing logic. Fixing the existing logic will be the subject of another series of changes. Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20220216155832.680775-4-ebiederm@xmission.com Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-17ucounts: Base set_cred_ucounts changes on the real userEric W. Biederman
Michal Koutný <mkoutny@suse.com> wrote: > Tasks are associated to multiple users at once. Historically and as per > setrlimit(2) RLIMIT_NPROC is enforce based on real user ID. > > The commit 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") > made the accounting structure "indexed" by euid and hence potentially > account tasks differently. > > The effective user ID may be different e.g. for setuid programs but > those are exec'd into already existing task (i.e. below limit), so > different accounting is moot. > > Some special setresuid(2) users may notice the difference, justifying > this fix. I looked at cred->ucount and it is only used for rlimit operations that were previously stored in cred->user. Making the fact cred->ucount can refer to a different user from cred->user a bug, affecting all uses of cred->ulimit not just RLIMIT_NPROC. Fix set_cred_ucounts to always use the real uid not the effective uid. Further simplify set_cred_ucounts by noticing that set_cred_ucounts somehow retained a draft version of the check to see if alloc_ucounts was needed that checks the new->user and new->user_ns against the current_real_cred(). Remove that draft version of the check. All that matters for setting the cred->ucounts are the user_ns and uid fields in the cred. Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20220207121800.5079-4-mkoutny@suse.com Link: https://lkml.kernel.org/r/20220216155832.680775-3-ebiederm@xmission.com Reported-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-17ucounts: Enforce RLIMIT_NPROC not RLIMIT_NPROC+1Eric W. Biederman
Michal Koutný <mkoutny@suse.com> wrote: > It was reported that v5.14 behaves differently when enforcing > RLIMIT_NPROC limit, namely, it allows one more task than previously. > This is consequence of the commit 21d1c5e386bc ("Reimplement > RLIMIT_NPROC on top of ucounts") that missed the sharpness of > equality in the forking path. This can be fixed either by fixing the test or by moving the increment to be before the test. Fix it my moving copy_creds which contains the increment before is_ucounts_overlimit. In the case of CLONE_NEWUSER the ucounts in the task_cred changes. The function is_ucounts_overlimit needs to use the final version of the ucounts for the new process. Which means moving the is_ucounts_overlimit test after copy_creds is necessary. Both the test in fork and the test in set_user were semantically changed when the code moved to ucounts. The change of the test in fork was bad because it was before the increment. The test in set_user was wrong and the change to ucounts fixed it. So this fix only restores the old behavior in one lcation not two. Link: https://lkml.kernel.org/r/20220204181144.24462-1-mkoutny@suse.com Link: https://lkml.kernel.org/r/20220216155832.680775-2-ebiederm@xmission.com Cc: stable@vger.kernel.org Reported-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-17rlimit: Fix RLIMIT_NPROC enforcement failure caused by capability calls in ↵Eric W. Biederman
set_user Solar Designer <solar@openwall.com> wrote: > I'm not aware of anyone actually running into this issue and reporting > it. The systems that I personally know use suexec along with rlimits > still run older/distro kernels, so would not yet be affected. > > So my mention was based on my understanding of how suexec works, and > code review. Specifically, Apache httpd has the setting RLimitNPROC, > which makes it set RLIMIT_NPROC: > > https://httpd.apache.org/docs/2.4/mod/core.html#rlimitnproc > > The above documentation for it includes: > > "This applies to processes forked from Apache httpd children servicing > requests, not the Apache httpd children themselves. This includes CGI > scripts and SSI exec commands, but not any processes forked from the > Apache httpd parent, such as piped logs." > > In code, there are: > > ./modules/generators/mod_cgid.c: ( (cgid_req.limits.limit_nproc_set) && ((rc = apr_procattr_limit_set(procattr, APR_LIMIT_NPROC, > ./modules/generators/mod_cgi.c: ((rc = apr_procattr_limit_set(procattr, APR_LIMIT_NPROC, > ./modules/filters/mod_ext_filter.c: rv = apr_procattr_limit_set(procattr, APR_LIMIT_NPROC, conf->limit_nproc); > > For example, in mod_cgi.c this is in run_cgi_child(). > > I think this means an httpd child sets RLIMIT_NPROC shortly before it > execs suexec, which is a SUID root program. suexec then switches to the > target user and execs the CGI script. > > Before 2863643fb8b9, the setuid() in suexec would set the flag, and the > target user's process count would be checked against RLIMIT_NPROC on > execve(). After 2863643fb8b9, the setuid() in suexec wouldn't set the > flag because setuid() is (naturally) called when the process is still > running as root (thus, has those limits bypass capabilities), and > accordingly execve() would not check the target user's process count > against RLIMIT_NPROC. In commit 2863643fb8b9 ("set_user: add capability check when rlimit(RLIMIT_NPROC) exceeds") capable calls were added to set_user to make it more consistent with fork. Unfortunately because of call site differences those capable calls were checking the credentials of the user before set*id() instead of after set*id(). This breaks enforcement of RLIMIT_NPROC for applications that set the rlimit and then call set*id() while holding a full set of capabilities. The capabilities are only changed in the new credential in security_task_fix_setuid(). The code in apache suexec appears to follow this pattern. Commit 909cc4ae86f3 ("[PATCH] Fix two bugs with process limits (RLIMIT_NPROC)") where this check was added describes the targes of this capability check as: 2/ When a root-owned process (e.g. cgiwrap) sets up process limits and then calls setuid, the setuid should fail if the user would then be running more than rlim_cur[RLIMIT_NPROC] processes, but it doesn't. This patch adds an appropriate test. With this patch, and per-user process limit imposed in cgiwrap really works. So the original use case of this check also appears to match the broken pattern. Restore the enforcement of RLIMIT_NPROC by removing the bad capable checks added in set_user. This unfortunately restores the inconsistent state the code has been in for the last 11 years, but dealing with the inconsistencies looks like a larger problem. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20210907213042.GA22626@openwall.com/ Link: https://lkml.kernel.org/r/20220212221412.GA29214@openwall.com Link: https://lkml.kernel.org/r/20220216155832.680775-1-ebiederm@xmission.com Fixes: 2863643fb8b9 ("set_user: add capability check when rlimit(RLIMIT_NPROC) exceeds") History-Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Reviewed-by: Solar Designer <solar@openwall.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-02-16module: fix building with sysfs disabledDmitry Torokhov
Sysfs support might be disabled so we need to guard the code that instantiates "compression" attribute with an #ifdef. Fixes: b1ae6dc41eaa ("module: add in-kernel support for decompressing") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-02-16bpf: Fix crash due to out of bounds access into reg2btf_ids.Kumar Kartikeya Dwivedi
When commit e6ac2450d6de ("bpf: Support bpf program calling kernel function") added kfunc support, it defined reg2btf_ids as a cheap way to translate the verifier reg type to the appropriate btf_vmlinux BTF ID, however commit c25b2ae13603 ("bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX | PTR_MAYBE_NULL") moved the __BPF_REG_TYPE_MAX from the last member of bpf_reg_type enum to after the base register types, and defined other variants using type flag composition. However, now, the direct usage of reg->type to index into reg2btf_ids may no longer fall into __BPF_REG_TYPE_MAX range, and hence lead to out of bounds access and kernel crash on dereference of bad pointer. Fixes: c25b2ae13603 ("bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX | PTR_MAYBE_NULL") Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220216201943.624869-1-memxor@gmail.com
2022-02-14cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplugZhang Qiao
As previously discussed(https://lkml.org/lkml/2022/1/20/51), cpuset_attach() is affected with similar cpu hotplug race, as follow scenario: cpuset_attach() cpu hotplug --------------------------- ---------------------- down_write(cpuset_rwsem) guarantee_online_cpus() // (load cpus_attach) sched_cpu_deactivate set_cpu_active() // will change cpu_active_mask set_cpus_allowed_ptr(cpus_attach) __set_cpus_allowed_ptr_locked() // (if the intersection of cpus_attach and cpu_active_mask is empty, will return -EINVAL) up_write(cpuset_rwsem) To avoid races such as described above, protect cpuset_attach() call with cpu_hotplug_lock. Fixes: be367d099270 ("cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time") Cc: stable@vger.kernel.org # v2.6.32+ Reported-by: Zhao Gongyi <zhaogongyi@huawei.com> Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com> Acked-by: Waiman Long <longman@redhat.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-14swiotlb: fix info leak with DMA_FROM_DEVICEHalil Pasic
The problem I'm addressing was discovered by the LTP test covering cve-2018-1000204. A short description of what happens follows: 1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device. 2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO. 3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV). 4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer. 5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails. One can argue that this is an swiotlb problem, because without swiotlb we leak all zeros, and the swiotlb should be transparent in a sense that it does not affect the outcome (if all other participants are well behaved). Copying the content of the original buffer into the swiotlb buffer is the only way I can think of to make swiotlb transparent in such scenarios. So let's do just that if in doubt, but allow the driver to tell us that the whole mapped buffer is going to be overwritten, in which case we can preserve the old behavior and avoid the performance impact of the extra bounce. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-02-13Merge tag 'sched_urgent_for_v5.17_rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Borislav Petkov: "Fix a NULL-ptr dereference when recalculating a sched entity's weight" * tag 'sched_urgent_for_v5.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix fault in reweight_entity
2022-02-13Merge tag 'perf_urgent_for_v5.17_rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fix from Borislav Petkov: "Prevent cgroup event list corruption when switching events" * tag 'perf_urgent_for_v5.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix list corruption in perf_cgroup_switch()
2022-02-12Merge tag 'seccomp-v5.17-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull seccomp fixes from Kees Cook: "This fixes a corner case of fatal SIGSYS being ignored since v5.15. Along with the signal fix is a change to seccomp so that seeing another syscall after a fatal filter result will cause seccomp to kill the process harder. Summary: - Force HANDLER_EXIT even for SIGNAL_UNKILLABLE - Make seccomp self-destruct after fatal filter results - Update seccomp samples for easier behavioral demonstration" * tag 'seccomp-v5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: samples/seccomp: Adjust sample to also provide kill option seccomp: Invalidate seccomp mode to catch death failures signal: HANDLER_EXIT should clear SIGNAL_UNKILLABLE
2022-02-11lockdep: Correct lock_classes index mappingCheng Jui Wang
A kernel exception was hit when trying to dump /proc/lockdep_chains after lockdep report "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!": Unable to handle kernel paging request at virtual address 00054005450e05c3 ... 00054005450e05c3] address between user and kernel address ranges ... pc : [0xffffffece769b3a8] string+0x50/0x10c lr : [0xffffffece769ac88] vsnprintf+0x468/0x69c ... Call trace: string+0x50/0x10c vsnprintf+0x468/0x69c seq_printf+0x8c/0xd8 print_name+0x64/0xf4 lc_show+0xb8/0x128 seq_read_iter+0x3cc/0x5fc proc_reg_read_iter+0xdc/0x1d4 The cause of the problem is the function lock_chain_get_class() will shift lock_classes index by 1, but the index don't need to be shifted anymore since commit 01bb6f0af992 ("locking/lockdep: Change the range of class_idx in held_lock struct") already change the index to start from 0. The lock_classes[-1] located at chain_hlocks array. When printing lock_classes[-1] after the chain_hlocks entries are modified, the exception happened. The output of lockdep_chains are incorrect due to this problem too. Fixes: f611e8cf98ec ("lockdep: Take read/write status in consideration when generate chainkey") Signed-off-by: Cheng Jui Wang <cheng-jui.wang@mediatek.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20220210105011.21712-1-cheng-jui.wang@mediatek.com
2022-02-11bpf: Emit bpf_timer in vmlinux BTFYonghong Song
Currently the following code in check_and_init_map_value() *(struct bpf_timer *)(dst + map->timer_off) = (struct bpf_timer){}; can help generate bpf_timer definition in vmlinuxBTF. But the code above may not zero the whole structure due to anonymour members and that code will be replaced by memset in the subsequent patch and bpf_timer definition will disappear from vmlinuxBTF. Let us emit the type explicitly so bpf program can continue to use it from vmlinux.h. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220211194948.3141529-1-yhs@fb.com
2022-02-11Merge tag 'acpi-5.17-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI fixes from Rafael Wysocki: "These revert two commits that turned out to be problematic and fix two issues related to wakeup from suspend-to-idle on x86. Specifics: - Revert a recent change that attempted to avoid issues with conflicting address ranges during PCI initialization, because it turned out to introduce a regression (Hans de Goede). - Revert a change that limited EC GPE wakeups from suspend-to-idle to systems based on Intel hardware, because it turned out that systems based on hardware from other vendors depended on that functionality too (Mario Limonciello). - Fix two issues related to the handling of wakeup interrupts and wakeup events signaled through the EC GPE during suspend-to-idle on x86 (Rafael Wysocki)" * tag 'acpi-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: x86/PCI: revert "Ignore E820 reservations for bridge windows on newer systems" PM: s2idle: ACPI: Fix wakeup interrupts handling ACPI: PM: s2idle: Cancel wakeup before dispatching EC GPE ACPI: PM: Revert "Only mark EC GPE for wakeup on Intel systems"
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