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2019-05-05Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull vfs fixes from Al Viro: - a couple of ->i_link use-after-free fixes - regression fix for wrong errno on absent device name in mount(2) (this cycle stuff) - ancient UFS braino in large GID handling on Solaris UFS images (bogus cut'n'paste from large UID handling; wrong field checked to decide whether we should look at old (16bit) or new (32bit) field) * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ufs: fix braino in ufs_get_inode_gid() for solaris UFS flavour Abort file_remove_privs() for non-reg. files [fix] get rid of checking for absent device name in vfs_get_tree() apparmorfs: fix use-after-free on symlink traversal securityfs: fix use-after-free on symlink traversal
2019-05-02Merge tag 'for-linus-20190502' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull io_uring fixes from Jens Axboe: "This is mostly io_uring fixes/tweaks. Most of these were actually done in time for the last -rc, but I wanted to ensure that everything tested out great before including them. The code delta looks larger than it really is, as it's mostly just comment additions/changes. Outside of the comment additions/changes, this is mostly removal of unnecessary barriers. In all, this pull request contains: - Tweak to how we handle errors at submission time. We now post a completion event if the error occurs on behalf of an sqe, instead of returning it through the system call. If the error happens outside of a specific sqe, we return the error through the system call. This makes it nicer to use and makes the "normal" use case behave the same as the offload cases. (me) - Fix for a missing req reference drop from async context (me) - If an sqe is submitted with RWF_NOWAIT, don't punt it to async context. Return -EAGAIN directly, instead of using it as a hint to do async punt. (Stefan) - Fix notes on barriers (Stefan) - Remove unnecessary barriers (Stefan) - Fix potential double free of memory in setup error (Mark) - Further improve sq poll CPU validation (Mark) - Fix page allocation warning and leak on buffer registration error (Mark) - Fix iov_iter_type() for new no-ref flag (Ming) - Fix a case where dio doesn't honor bio no-page-ref (Ming)" * tag 'for-linus-20190502' of git://git.kernel.dk/linux-block: io_uring: avoid page allocation warnings iov_iter: fix iov_iter_type block: fix handling for BIO_NO_PAGE_REF io_uring: drop req submit reference always in async punt io_uring: free allocated io_memory once io_uring: fix SQPOLL cpu validation io_uring: have submission side sqe errors post a cqe io_uring: remove unnecessary barrier after unsetting IORING_SQ_NEED_WAKEUP io_uring: remove unnecessary barrier after incrementing dropped counter io_uring: remove unnecessary barrier before reading SQ tail io_uring: remove unnecessary barrier after updating SQ head io_uring: remove unnecessary barrier before reading cq head io_uring: remove unnecessary barrier before wq_has_sleeper io_uring: fix notes on barriers io_uring: fix handling SQEs requesting NOWAIT
2019-05-02ufs: fix braino in ufs_get_inode_gid() for solaris UFS flavourAl Viro
To choose whether to pick the GID from the old (16bit) or new (32bit) field, we should check if the old gid field is set to 0xffff. Mainline checks the old *UID* field instead - cut'n'paste from the corresponding code in ufs_get_inode_uid(). Fixes: 252e211e90ce Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01gcc-9: don't warn about uninitialized btrfs extent_type variableLinus Torvalds
The 'extent_type' variable does seem to be reliably initialized, but it's _very_ non-obvious, since there's a "goto next" case that jumps over the normal initialization. That will then always trigger the "start >= extent_end" test, which will end up never falling through to the use of that variable. But the code is certainly not obvious, and the compiler warning looks reasonable. Make 'extent_type' an int, and initialize it to an invalid negative value, which seems to be the common pattern in other places. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-01io_uring: avoid page allocation warningsMark Rutland
In io_sqe_buffer_register() we allocate a number of arrays based on the iov_len from the user-provided iov. While we limit iov_len to SZ_1G, we can still attempt to allocate arrays exceeding MAX_ORDER. On a 64-bit system with 4KiB pages, for an iov where iov_base = 0x10 and iov_len = SZ_1G, we'll calculate that nr_pages = 262145. When we try to allocate a corresponding array of (16-byte) bio_vecs, requiring 4194320 bytes, which is greater than 4MiB. This results in SLUB warning that we're trying to allocate greater than MAX_ORDER, and failing the allocation. Avoid this by using kvmalloc() for allocations dependent on the user-provided iov_len. At the same time, fix a leak of imu->bvec when registration fails. Full splat from before this patch: WARNING: CPU: 1 PID: 2314 at mm/page_alloc.c:4595 __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2314 Comm: syz-executor326 Not tainted 5.1.0-rc7-dirty #4 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x2f0 include/linux/compiler.h:193 show_stack+0x20/0x30 arch/arm64/kernel/traps.c:158 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x110/0x190 lib/dump_stack.c:113 panic+0x384/0x68c kernel/panic.c:214 __warn+0x2bc/0x2c0 kernel/panic.c:571 report_bug+0x228/0x2d8 lib/bug.c:186 bug_handler+0xa0/0x1a0 arch/arm64/kernel/traps.c:956 call_break_hook arch/arm64/kernel/debug-monitors.c:301 [inline] brk_handler+0x1d4/0x388 arch/arm64/kernel/debug-monitors.c:316 do_debug_exception+0x1a0/0x468 arch/arm64/mm/fault.c:831 el1_dbg+0x18/0x8c __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 alloc_pages_current+0x164/0x278 mm/mempolicy.c:2132 alloc_pages include/linux/gfp.h:509 [inline] kmalloc_order+0x20/0x50 mm/slab_common.c:1231 kmalloc_order_trace+0x30/0x2b0 mm/slab_common.c:1243 kmalloc_large include/linux/slab.h:480 [inline] __kmalloc+0x3dc/0x4f0 mm/slub.c:3791 kmalloc_array include/linux/slab.h:670 [inline] io_sqe_buffer_register fs/io_uring.c:2472 [inline] __io_uring_register fs/io_uring.c:2962 [inline] __do_sys_io_uring_register fs/io_uring.c:3008 [inline] __se_sys_io_uring_register fs/io_uring.c:2990 [inline] __arm64_sys_io_uring_register+0x9e0/0x1bc8 fs/io_uring.c:2990 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall arch/arm64/kernel/syscall.c:47 [inline] el0_svc_common.constprop.0+0x148/0x2e0 arch/arm64/kernel/syscall.c:83 el0_svc_handler+0xdc/0x100 arch/arm64/kernel/syscall.c:129 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:948 SMP: stopping secondary CPUs Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled CPU features: 0x002,23000438 Memory Limit: none Rebooting in 1 seconds.. Fixes: edafccee56ff3167 ("io_uring: add support for pre-mapped user IO buffers") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01block: fix handling for BIO_NO_PAGE_REFMing Lei
Commit 399254aaf489211 ("block: add BIO_NO_PAGE_REF flag") introduces BIO_NO_PAGE_REF, and once this flag is set for one bio, all pages in the bio won't be get/put during IO. However, if one bio is submitted via __blkdev_direct_IO_simple(), even though BIO_NO_PAGE_REF is set, pages still may be put. Fixes this issue by avoiding to put pages if BIO_NO_PAGE_REF is set. Fixes: 399254aaf489211 ("block: add BIO_NO_PAGE_REF flag") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01io_uring: drop req submit reference always in async puntJens Axboe
If we don't end up actually calling submit in io_sq_wq_submit_work(), we still need to drop the submit reference to the request. If we don't, then we can leak the request. This can happen if we race with ring shutdown while flushing the workqueue for requests that require use of the mm_struct. Fixes: e65ef56db494 ("io_uring: use regular request ref counts") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01io_uring: free allocated io_memory onceMark Rutland
If io_allocate_scq_urings() fails to allocate an sq_* region, it will call io_mem_free() for any previously allocated regions, but leave dangling pointers to these regions in the ctx. Any regions which have not yet been allocated are left NULL. Note that when returning -EOVERFLOW, the previously allocated sq_ring is not freed, which appears to be an unintentional leak. When io_allocate_scq_urings() fails, io_uring_create() will call io_ring_ctx_wait_and_kill(), which calls io_mem_free() on all the sq_* regions, assuming the pointers are valid and not NULL. This can result in pages being freed multiple times, which has been observed to corrupt the page state, leading to subsequent fun. This can also result in virt_to_page() on NULL, resulting in the use of bogus page addresses, and yet more subsequent fun. The latter can be detected with CONFIG_DEBUG_VIRTUAL on arm64. Adding a cleanup path to io_allocate_scq_urings() complicates the logic, so let's leave it to io_ring_ctx_free() to consistently free these pointers, and simplify the io_allocate_scq_urings() error paths. Full splats from before this patch below. Note that the pointer logged by the DEBUG_VIRTUAL "non-linear address" warning has been hashed, and is actually NULL. [ 26.098129] page:ffff80000e949a00 count:0 mapcount:-128 mapping:0000000000000000 index:0x0 [ 26.102976] flags: 0x63fffc000000() [ 26.104373] raw: 000063fffc000000 ffff80000e86c188 ffff80000ea3df08 0000000000000000 [ 26.108917] raw: 0000000000000000 0000000000000001 00000000ffffff7f 0000000000000000 [ 26.137235] page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0) [ 26.143960] ------------[ cut here ]------------ [ 26.146020] kernel BUG at include/linux/mm.h:547! [ 26.147586] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 26.149163] Modules linked in: [ 26.150287] Process syz-executor.21 (pid: 20204, stack limit = 0x000000000e9cefeb) [ 26.153307] CPU: 2 PID: 20204 Comm: syz-executor.21 Not tainted 5.1.0-rc7-00004-g7d30b2ea43d6 #18 [ 26.156566] Hardware name: linux,dummy-virt (DT) [ 26.158089] pstate: 40400005 (nZcv daif +PAN -UAO) [ 26.159869] pc : io_mem_free+0x9c/0xa8 [ 26.161436] lr : io_mem_free+0x9c/0xa8 [ 26.162720] sp : ffff000013003d60 [ 26.164048] x29: ffff000013003d60 x28: ffff800025048040 [ 26.165804] x27: 0000000000000000 x26: ffff800025048040 [ 26.167352] x25: 00000000000000c0 x24: ffff0000112c2820 [ 26.169682] x23: 0000000000000000 x22: 0000000020000080 [ 26.171899] x21: ffff80002143b418 x20: ffff80002143b400 [ 26.174236] x19: ffff80002143b280 x18: 0000000000000000 [ 26.176607] x17: 0000000000000000 x16: 0000000000000000 [ 26.178997] x15: 0000000000000000 x14: 0000000000000000 [ 26.181508] x13: 00009178a5e077b2 x12: 0000000000000001 [ 26.183863] x11: 0000000000000000 x10: 0000000000000980 [ 26.186437] x9 : ffff000013003a80 x8 : ffff800025048a20 [ 26.189006] x7 : ffff8000250481c0 x6 : ffff80002ffe9118 [ 26.191359] x5 : ffff80002ffe9118 x4 : 0000000000000000 [ 26.193863] x3 : ffff80002ffefe98 x2 : 44c06ddd107d1f00 [ 26.196642] x1 : 0000000000000000 x0 : 000000000000003e [ 26.198892] Call trace: [ 26.199893] io_mem_free+0x9c/0xa8 [ 26.201155] io_ring_ctx_wait_and_kill+0xec/0x180 [ 26.202688] io_uring_setup+0x6c4/0x6f0 [ 26.204091] __arm64_sys_io_uring_setup+0x18/0x20 [ 26.205576] el0_svc_common.constprop.0+0x7c/0xe8 [ 26.207186] el0_svc_handler+0x28/0x78 [ 26.208389] el0_svc+0x8/0xc [ 26.209408] Code: aa0203e0 d0006861 9133a021 97fcdc3c (d4210000) [ 26.211995] ---[ end trace bdb81cd43a21e50d ]--- [ 81.770626] ------------[ cut here ]------------ [ 81.825015] virt_to_phys used for non-linear address: 000000000d42f2c7 ( (null)) [ 81.827860] WARNING: CPU: 1 PID: 30171 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x48/0x68 [ 81.831202] Modules linked in: [ 81.832212] CPU: 1 PID: 30171 Comm: syz-executor.20 Not tainted 5.1.0-rc7-00004-g7d30b2ea43d6 #19 [ 81.835616] Hardware name: linux,dummy-virt (DT) [ 81.836863] pstate: 60400005 (nZCv daif +PAN -UAO) [ 81.838727] pc : __virt_to_phys+0x48/0x68 [ 81.840572] lr : __virt_to_phys+0x48/0x68 [ 81.842264] sp : ffff80002cf67c70 [ 81.843858] x29: ffff80002cf67c70 x28: ffff800014358e18 [ 81.846463] x27: 0000000000000000 x26: 0000000020000080 [ 81.849148] x25: 0000000000000000 x24: ffff80001bb01f40 [ 81.851986] x23: ffff200011db06c8 x22: ffff2000127e3c60 [ 81.854351] x21: ffff800014358cc0 x20: ffff800014358d98 [ 81.856711] x19: 0000000000000000 x18: 0000000000000000 [ 81.859132] x17: 0000000000000000 x16: 0000000000000000 [ 81.861586] x15: 0000000000000000 x14: 0000000000000000 [ 81.863905] x13: 0000000000000000 x12: ffff1000037603e9 [ 81.866226] x11: 1ffff000037603e8 x10: 0000000000000980 [ 81.868776] x9 : ffff80002cf67840 x8 : ffff80001bb02920 [ 81.873272] x7 : ffff1000037603e9 x6 : ffff80001bb01f47 [ 81.875266] x5 : ffff1000037603e9 x4 : dfff200000000000 [ 81.876875] x3 : ffff200010087528 x2 : ffff1000059ecf58 [ 81.878751] x1 : 44c06ddd107d1f00 x0 : 0000000000000000 [ 81.880453] Call trace: [ 81.881164] __virt_to_phys+0x48/0x68 [ 81.882919] io_mem_free+0x18/0x110 [ 81.886585] io_ring_ctx_wait_and_kill+0x13c/0x1f0 [ 81.891212] io_uring_setup+0xa60/0xad0 [ 81.892881] __arm64_sys_io_uring_setup+0x2c/0x38 [ 81.894398] el0_svc_common.constprop.0+0xac/0x150 [ 81.896306] el0_svc_handler+0x34/0x88 [ 81.897744] el0_svc+0x8/0xc [ 81.898715] ---[ end trace b4a703802243cbba ]--- Fixes: 2b188cc1bb857a9d ("Add io_uring IO interface") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01io_uring: fix SQPOLL cpu validationMark Rutland
In io_sq_offload_start(), we call cpu_possible() on an unbounded cpu value from userspace. On v5.1-rc7 on arm64 with CONFIG_DEBUG_PER_CPU_MAPS, this results in a splat: WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpu_max_bits_warn include/linux/cpumask.h:121 [inline] There was an attempt to fix this in commit: 917257daa0fea7a0 ("io_uring: only test SQPOLL cpu after we've verified it") ... by adding a check after the cpu value had been limited to NR_CPU_IDS using array_index_nospec(). However, this left an unbound check at the start of the function, for which the warning still fires. Let's fix this correctly by checking that the cpu value is bound by nr_cpu_ids before passing it to cpu_possible(). Note that only nr_cpu_ids of a cpumask are guaranteed to exist at runtime, and nr_cpu_ids can be significantly smaller than NR_CPUs. For example, an arm64 defconfig has NR_CPUS=256, while my test VM has 4 vCPUs. Following the intent from the commit message for 917257daa0fea7a0, the check is moved under the SQ_AFF branch, which is the only branch where the cpu values is consumed. The check is performed before bounding the value with array_index_nospec() so that we don't silently accept bogus cpu values from userspace, where array_index_nospec() would force these values to 0. I suspect we can remove the array_index_nospec() call entirely, but I've conservatively left that in place, updated to use nr_cpu_ids to match the prior check. Tested on arm64 with the Syzkaller reproducer: https://syzkaller.appspot.com/bug?extid=cd714a07c6de2bc34293 https://syzkaller.appspot.com/x/repro.syz?x=15d8b397200000 Full splat from before this patch: WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpu_max_bits_warn include/linux/cpumask.h:121 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpumask_check include/linux/cpumask.h:128 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpumask_test_cpu include/linux/cpumask.h:344 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 io_sq_offload_start fs/io_uring.c:2244 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 io_uring_create fs/io_uring.c:2864 [inline] WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 io_uring_setup+0x1108/0x15a0 fs/io_uring.c:2916 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 27601 Comm: syz-executor.0 Not tainted 5.1.0-rc7 #3 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x2f0 include/linux/compiler.h:193 show_stack+0x20/0x30 arch/arm64/kernel/traps.c:158 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x110/0x190 lib/dump_stack.c:113 panic+0x384/0x68c kernel/panic.c:214 __warn+0x2bc/0x2c0 kernel/panic.c:571 report_bug+0x228/0x2d8 lib/bug.c:186 bug_handler+0xa0/0x1a0 arch/arm64/kernel/traps.c:956 call_break_hook arch/arm64/kernel/debug-monitors.c:301 [inline] brk_handler+0x1d4/0x388 arch/arm64/kernel/debug-monitors.c:316 do_debug_exception+0x1a0/0x468 arch/arm64/mm/fault.c:831 el1_dbg+0x18/0x8c cpu_max_bits_warn include/linux/cpumask.h:121 [inline] cpumask_check include/linux/cpumask.h:128 [inline] cpumask_test_cpu include/linux/cpumask.h:344 [inline] io_sq_offload_start fs/io_uring.c:2244 [inline] io_uring_create fs/io_uring.c:2864 [inline] io_uring_setup+0x1108/0x15a0 fs/io_uring.c:2916 __do_sys_io_uring_setup fs/io_uring.c:2929 [inline] __se_sys_io_uring_setup fs/io_uring.c:2926 [inline] __arm64_sys_io_uring_setup+0x50/0x70 fs/io_uring.c:2926 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall arch/arm64/kernel/syscall.c:47 [inline] el0_svc_common.constprop.0+0x148/0x2e0 arch/arm64/kernel/syscall.c:83 el0_svc_handler+0xdc/0x100 arch/arm64/kernel/syscall.c:129 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:948 SMP: stopping secondary CPUs Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled CPU features: 0x002,23000438 Memory Limit: none Rebooting in 1 seconds.. Fixes: 917257daa0fea7a0 ("io_uring: only test SQPOLL cpu after we've verified it") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Simplied the logic Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01io_uring: have submission side sqe errors post a cqeJens Axboe
Currently we only post a cqe if we get an error OUTSIDE of submission. For submission, we return the error directly through io_uring_enter(). This is a bit awkward for applications, and it makes more sense to always post a cqe with an error, if the error happens on behalf of an sqe. This changes submission behavior a bit. io_uring_enter() returns -ERROR for an error, and > 0 for number of sqes submitted. Before this change, if you wanted to submit 8 entries and had an error on the 5th entry, io_uring_enter() would return 4 (for number of entries successfully submitted) and rewind the sqring. The application would then have to peek at the sqring and figure out what was wrong with the head sqe, and then skip it itself. With this change, we'll return 5 since we did consume 5 sqes, and the last sqe (with the error) will result in a cqe being posted with the error. This makes the logic easier to handle in the application, and it cleans up the submission part. Suggested-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30Merge tag 'fsnotify_for_v5.1-rc8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify fix from Jan Kara: "A fix of user trigerable NULL pointer dereference syzbot has recently spotted. The problem was introduced in this merge window so no CC stable is needed" * tag 'fsnotify_for_v5.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: Fix NULL ptr deref in fanotify_get_fsid()
2019-04-30io_uring: remove unnecessary barrier after unsetting IORING_SQ_NEED_WAKEUPStefan Bühler
There is no operation to order with afterwards, and removing the flag is not critical in any way. There will always be a "race condition" where the application will trigger IORING_ENTER_SQ_WAKEUP when it isn't actually needed. Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30io_uring: remove unnecessary barrier after incrementing dropped counterStefan Bühler
smp_store_release in io_commit_sqring already orders the store to dropped before the update to SQ head. Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30io_uring: remove unnecessary barrier before reading SQ tailStefan Bühler
There is no operation before to order with. Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30io_uring: remove unnecessary barrier after updating SQ headStefan Bühler
There is no operation afterwards to order with. Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30io_uring: remove unnecessary barrier before reading cq headStefan Bühler
The memory operations before reading cq head are unrelated and we don't care about their order. Document that the control dependency in combination with READ_ONCE and WRITE_ONCE forms a barrier we need. Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30io_uring: remove unnecessary barrier before wq_has_sleeperStefan Bühler
wq_has_sleeper has a full barrier internally. The smp_rmb barrier in io_uring_poll synchronizes with it. Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30io_uring: fix notes on barriersStefan Bühler
The application reading the CQ ring needs a barrier to pair with the smp_store_release in io_commit_cqring, not the barrier after it. Also a write barrier *after* writing something (but not *before* writing anything interesting) doesn't order anything, so an smp_wmb() after writing SQ tail is not needed. Additionally consider reading SQ head and writing CQ tail in the notes. Also add some clarifications how the various other fields in the ring buffers are used. Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30io_uring: fix handling SQEs requesting NOWAITStefan Bühler
Not all request types set REQ_F_FORCE_NONBLOCK when they needed async punting; reverse logic instead and set REQ_F_NOWAIT if request mustn't be punted. Signed-off-by: Stefan Bühler <source@stbuehler.de> Merged with my previous patch for this. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-28Abort file_remove_privs() for non-reg. filesAlexander Lochmann
file_remove_privs() might be called for non-regular files, e.g. blkdev inode. There is no reason to do its job on things like blkdev inodes, pipes, or cdevs. Hence, abort if file does not refer to a regular inode. AV: more to the point, for devices there might be any number of inodes refering to given device. Which one to strip the permissions from, even if that made any sense in the first place? All of them will be observed with contents modified, after all. Found by LockDoc (Alexander Lochmann, Horst Schirmeier and Olaf Spinczyk) Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Alexander Lochmann <alexander.lochmann@tu-dortmund.de> Signed-off-by: Horst Schirmeier <horst.schirmeier@tu-dortmund.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-28[fix] get rid of checking for absent device name in vfs_get_tree()Al Viro
It has no business being there, it's checked by relevant ->get_tree() as it is *and* it returns the wrong error for no reason whatsoever. Fixes: f3a09c92018a "introduce fs_context methods" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-28fsnotify: Fix NULL ptr deref in fanotify_get_fsid()Jan Kara
fanotify_get_fsid() is reading mark->connector->fsid under srcu. It can happen that it sees mark not fully initialized or mark that is already detached from the object list. In these cases mark->connector can be NULL leading to NULL ptr dereference. Fix the problem by being careful when reading mark->connector and check it for being NULL. Also use WRITE_ONCE when writing the mark just to prevent compiler from doing something stupid. Reported-by: syzbot+15927486a4f1bfcbaf91@syzkaller.appspotmail.com Fixes: 77115225acc6 ("fanotify: cache fsid in fsnotify_mark_connector") Signed-off-by: Jan Kara <jack@suse.cz>
2019-04-28Merge tag 'for-linus-20190428' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A set of io_uring fixes that should go into this release. In particular, this contains: - The mutex lock vs ctx ref count fix (me) - Removal of a dead variable (me) - Two race fixes (Stefan) - Ring head/tail condition fix for poll full SQ detection (Stefan)" * tag 'for-linus-20190428' of git://git.kernel.dk/linux-block: io_uring: remove 'state' argument from io_{read,write} path io_uring: fix poll full SQ detection io_uring: fix race condition when sq threads goes sleeping io_uring: fix race condition reading SQ entries io_uring: fail io_uring_register(2) on a dying io_uring instance
2019-04-26Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "9 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: fs/proc/proc_sysctl.c: Fix a NULL pointer dereference mm/page_alloc.c: fix never set ALLOC_NOFRAGMENT flag mm/page_alloc.c: avoid potential NULL pointer dereference mm, page_alloc: always use a captured page regardless of compaction result mm: do not boost watermarks to avoid fragmentation for the DISCONTIG memory model lib/test_vmalloc.c: do not create cpumask_t variable on stack lib/Kconfig.debug: fix build error without CONFIG_BLOCK zram: pass down the bvec we need to read into in the work struct mm/memory_hotplug.c: drop memory device reference after find_memory_block()
2019-04-26Merge tag 'trace-v5.1-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Three tracing fixes: - Use "nosteal" for ring buffer splice pages - Memory leak fix in error path of trace_pid_write() - Fix preempt_enable_no_resched() (use preempt_enable()) in ring buffer code" * tag 'trace-v5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: trace: Fix preempt_enable_no_resched() abuse tracing: Fix a memory leak by early error exit in trace_pid_write() tracing: Fix buffer_ref pipe ops
2019-04-26Merge tag 'for-5.1-rc6-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "One patch to fix a crash in io submission path, due to memory allocation errors. In short, the multipage bio work that landed in 5.1 caused larger bios that in turn require larger temporary memory for checksums. The patch is a workaround, we're going to rework the allocation so it does not require the vmalloc fallback. It took a while to identify that it's caused by patches in 5.1 and not a patchset that did some changes in error handling in the code. I've tested it on various memory/cpu combinations, it could hit OOM but does not crash. The timestamp of the patch is less than a day due to updates in the changelog, tests were running meanwhile" * tag 'for-5.1-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: Switch memory allocations in async csum calculation path to kvmalloc
2019-04-26Merge tag '5.1-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull cifs fixes from Steve French: "Three small SMB3 fixes (all for stable as well): two leaks and a rename bug" * tag '5.1-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: fix page reference leak with readv/writev cifs: do not attempt cifs operation on smb2+ rename error cifs: fix memory leak in SMB2_read
2019-04-26fs/proc/proc_sysctl.c: Fix a NULL pointer dereferenceYueHaibing
Syzkaller report this: sysctl could not get directory: /net//bridge -12 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN PTI CPU: 1 PID: 7027 Comm: syz-executor.0 Tainted: G C 5.1.0-rc3+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 RIP: 0010:__write_once_size include/linux/compiler.h:220 [inline] RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:144 [inline] RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:186 [inline] RIP: 0010:rb_erase+0x5f4/0x19f0 lib/rbtree.c:459 Code: 00 0f 85 60 13 00 00 48 89 1a 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 75 0c 00 00 4d 85 ed 4c 89 2e 74 ce 4c 89 ea 48 RSP: 0018:ffff8881bb507778 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff8881f224b5b8 RCX: ffffffff818f3f6a RDX: 000000000000000a RSI: 0000000000000050 RDI: ffff8881f224b568 RBP: 0000000000000000 R08: ffffed10376a0ef4 R09: ffffed10376a0ef4 R10: 0000000000000001 R11: ffffed10376a0ef4 R12: ffff8881f224b558 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f3e7ce13700(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd60fbe9398 CR3: 00000001cb55c001 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: erase_entry fs/proc/proc_sysctl.c:178 [inline] erase_header+0xe3/0x160 fs/proc/proc_sysctl.c:207 start_unregistering fs/proc/proc_sysctl.c:331 [inline] drop_sysctl_table+0x558/0x880 fs/proc/proc_sysctl.c:1631 get_subdir fs/proc/proc_sysctl.c:1022 [inline] __register_sysctl_table+0xd65/0x1090 fs/proc/proc_sysctl.c:1335 br_netfilter_init+0x68/0x1000 [br_netfilter] do_one_initcall+0xbc/0x47d init/main.c:901 do_init_module+0x1b5/0x547 kernel/module.c:3456 load_module+0x6405/0x8c10 kernel/module.c:3804 __do_sys_finit_module+0x162/0x190 kernel/module.c:3898 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Modules linked in: br_netfilter(+) backlight comedi(C) hid_sensor_hub max3100 ti_ads8688 udc_core fddi snd_mona leds_gpio rc_streamzap mtd pata_netcell nf_log_common rc_winfast udp_tunnel snd_usbmidi_lib snd_usb_toneport snd_usb_line6 snd_rawmidi snd_seq_device snd_hwdep videobuf2_v4l2 videobuf2_common videodev media videobuf2_vmalloc videobuf2_memops rc_gadmei_rm008z 8250_of smm665 hid_tmff hid_saitek hwmon_vid rc_ati_tv_wonder_hd_600 rc_core pata_pdc202xx_old dn_rtmsg as3722 ad714x_i2c ad714x snd_soc_cs4265 hid_kensington panel_ilitek_ili9322 drm drm_panel_orientation_quirks ipack cdc_phonet usbcore phonet hid_jabra hid extcon_arizona can_dev industrialio_triggered_buffer kfifo_buf industrialio adm1031 i2c_mux_ltc4306 i2c_mux ipmi_msghandler mlxsw_core snd_soc_cs35l34 snd_soc_core snd_pcm_dmaengine snd_pcm snd_timer ac97_bus snd_compress snd soundcore gpio_da9055 uio ecdh_generic mdio_thunder of_mdio fixed_phy libphy mdio_cavium iptable_security iptable_raw iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun joydev mousedev ppdev tpm kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel ide_pci_generic piix aes_x86_64 crypto_simd cryptd ide_core glue_helper input_leds psmouse intel_agp intel_gtt serio_raw ata_generic i2c_piix4 agpgart pata_acpi parport_pc parport floppy rtc_cmos sch_fq_codel ip_tables x_tables sha1_ssse3 sha1_generic ipv6 [last unloaded: br_netfilter] Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace 68741688d5fbfe85 ]--- commit 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links") forgot to handle start_unregistering() case, while header->parent is NULL, it calls erase_header() and as seen in the above syzkaller call trace, accessing &header->parent->root will trigger a NULL pointer dereference. As that commit explained, there is also no need to call start_unregistering() if header->parent is NULL. Link: http://lkml.kernel.org/r/20190409153622.28112-1-yuehaibing@huawei.com Fixes: 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links") Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26tracing: Fix buffer_ref pipe opsJann Horn
This fixes multiple issues in buffer_pipe_buf_ops: - The ->steal() handler must not return zero unless the pipe buffer has the only reference to the page. But generic_pipe_buf_steal() assumes that every reference to the pipe is tracked by the page's refcount, which isn't true for these buffers - buffer_pipe_buf_get(), which duplicates a buffer, doesn't touch the page's refcount. Fix it by using generic_pipe_buf_nosteal(), which refuses every attempted theft. It should be easy to actually support ->steal, but the only current users of pipe_buf_steal() are the virtio console and FUSE, and they also only use it as an optimization. So it's probably not worth the effort. - The ->get() and ->release() handlers can be invoked concurrently on pipe buffers backed by the same struct buffer_ref. Make them safe against concurrency by using refcount_t. - The pointers stored in ->private were only zeroed out when the last reference to the buffer_ref was dropped. As far as I know, this shouldn't be necessary anyway, but if we do it, let's always do it. Link: http://lkml.kernel.org/r/20190404215925.253531-1-jannh@google.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org Fixes: 73a757e63114d ("ring-buffer: Return reader page back into existing ring buffer") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-25Merge tag 'ceph-for-5.1-rc7' of git://github.com/ceph/ceph-clientLinus Torvalds
Pull ceph fixes from Ilya Dryomov: "dentry name handling fixes from Jeff and a memory leak fix from Zheng. Both are old issues, marked for stable" * tag 'ceph-for-5.1-rc7' of git://github.com/ceph/ceph-client: ceph: fix ci->i_head_snapc leak ceph: handle the case where a dentry has been renamed on outstanding req ceph: ensure d_name stability in ceph_dentry_hash() ceph: only use d_name directly when parent is locked
2019-04-25btrfs: Switch memory allocations in async csum calculation path to kvmallocNikolay Borisov
Recent multi-page biovec rework allowed creation of bios that can span large regions - up to 128 megabytes in the case of btrfs. OTOH btrfs' submission path currently allocates a contiguous array to store the checksums for every bio submitted. This means we can request up to (128mb / BTRFS_SECTOR_SIZE) * 4 bytes + 32bytes of memory from kmalloc. On busy systems with possibly fragmented memory said kmalloc can fail which will trigger BUG_ON due to improper error handling IO submission context in btrfs. Until error handling is improved or bios in btrfs limited to a more manageable size (e.g. 1m) let's use kvmalloc to fallback to vmalloc for such large allocations. There is no hard requirement that the memory allocated for checksums during IO submission has to be contiguous, but this is a simple fix that does not require several non-contiguous allocations. For small writes this is unlikely to have any visible effect since kmalloc will still satisfy allocation requests as usual. For larger requests the code will just fallback to vmalloc. We've performed evaluation on several workload types and there was no significant difference kmalloc vs kvmalloc. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-24cifs: fix page reference leak with readv/writevJérôme Glisse
CIFS can leak pages reference gotten through GUP (get_user_pages*() through iov_iter_get_pages()). This happen if cifs_send_async_read() or cifs_write_from_iter() calls fail from within __cifs_readv() and __cifs_writev() respectively. This patch move page unreference to cifs_aio_ctx_release() which will happens on all code paths this is all simpler to follow for correctness. Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Steve French <sfrench@samba.org> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-04-24cifs: do not attempt cifs operation on smb2+ rename errorFrank Sorenson
A path-based rename returning EBUSY will incorrectly try opening the file with a cifs (NT Create AndX) operation on an smb2+ mount, which causes the server to force a session close. If the mount is smb2+, skip the fallback. Signed-off-by: Frank Sorenson <sorenson@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-04-24cifs: fix memory leak in SMB2_readRonnie Sahlberg
Commit 088aaf17aa79300cab14dbee2569c58cfafd7d6e introduced a leak where if SMB2_read() returned an error we would return without freeing the request buffer. Cc: Stable <stable@vger.kernel.org> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-04-23Merge tag 'nfsd-5.1-1' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
Pull nfsd bugfixes from Bruce Fields: "Fix miscellaneous nfsd bugs, in NFSv4.1 callbacks, NFSv4.1 lock-notification callbacks, NFSv3 readdir encoding, and the cache/upcall code" * tag 'nfsd-5.1-1' of git://linux-nfs.org/~bfields/linux: nfsd: wake blocked file lock waiters before sending callback nfsd: wake waiters blocked on file_lock before deleting it nfsd: Don't release the callback slot unless it was actually held nfsd/nfsd3_proc_readdir: fix buffer count and page pointers sunrpc: don't mark uninitialised items as VALID.
2019-04-23ceph: fix ci->i_head_snapc leakYan, Zheng
We missed two places that i_wrbuffer_ref_head, i_wr_ref, i_dirty_caps and i_flushing_caps may change. When they are all zeros, we should free i_head_snapc. Cc: stable@vger.kernel.org Link: https://tracker.ceph.com/issues/38224 Reported-and-tested-by: Luis Henriques <lhenriques@suse.com> Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-04-23ceph: handle the case where a dentry has been renamed on outstanding reqJeff Layton
It's possible for us to issue a lookup to revalidate a dentry concurrently with a rename. If done in the right order, then we could end up processing dentry info in the reply that no longer reflects the state of the dentry. If req->r_dentry->d_name differs from the one in the trace, then just ignore the trace in the reply. We only need to do this however if the parent's i_rwsem is not held. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-04-23ceph: ensure d_name stability in ceph_dentry_hash()Jeff Layton
Take the d_lock here to ensure that d_name doesn't change. Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-04-23ceph: only use d_name directly when parent is lockedJeff Layton
Ben reported tripping the BUG_ON in create_request_message during some performance testing. Analysis of the vmcore showed that the length of the r_dentry->d_name string changed after we allocated the buffer, but before we encoded it. build_dentry_path returns pointers to d_name in the common case of non-snapped dentries, but this optimization isn't safe unless the parent directory is locked. When it isn't, have the code make a copy of the d_name while holding the d_lock. Cc: stable@vger.kernel.org Reported-by: Ben England <bengland@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-04-23io_uring: remove 'state' argument from io_{read,write} pathJens Axboe
Since commit 09bb839434b we don't use the state argument for any sort of on-stack caching in the io read and write path. Remove the stale and unused argument from them, and bubble it up to __io_submit_sqe() and down to io_prep_rw(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22nfsd: wake blocked file lock waiters before sending callbackJeff Layton
When a blocked NFS lock is "awoken" we send a callback to the server and then wake any hosts waiting on it. If a client attempts to get a lock and then drops off the net, we could end up waiting for a long time until we end up waking locks blocked on that request. So, wake any other waiting lock requests before sending the callback. Do this by calling locks_delete_block in a new "prepare" phase for CB_NOTIFY_LOCK callbacks. URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363 Fixes: 16306a61d3b7 ("fs/locks: always delete_block after waiting.") Reported-by: Slawomir Pryczek <slawek1211@gmail.com> Cc: Neil Brown <neilb@suse.com> Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-22nfsd: wake waiters blocked on file_lock before deleting itJeff Layton
After a blocked nfsd file_lock request is deleted, knfsd will send a callback to the client and then free the request. Commit 16306a61d3b7 ("fs/locks: always delete_block after waiting.") changed it such that locks_delete_block is always called on a request after it is awoken, but that patch missed fixing up blocked nfsd request handling. Call locks_delete_block on the block to wake up any locks still blocked on the nfsd lock request before freeing it. Some of its callers already do this however, so just remove those calls. URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363 Fixes: 16306a61d3b7 ("fs/locks: always delete_block after waiting.") Reported-by: Slawomir Pryczek <slawek1211@gmail.com> Cc: Neil Brown <neilb@suse.com> Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-22io_uring: fix poll full SQ detectionStefan Bühler
io_uring_poll shouldn't signal EPOLLOUT | EPOLLWRNORM if the queue is full; the old check would always signal EPOLLOUT | EPOLLWRNORM (unless there were U32_MAX - 1 entries in the SQ queue). Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22io_uring: fix race condition when sq threads goes sleepingStefan Bühler
Reading the SQ tail needs to come after setting IORING_SQ_NEED_WAKEUP in flags; there is no cheap barrier for ordering a store before a load, a full memory barrier is required. Userspace needs a full memory barrier between updating SQ tail and checking for the IORING_SQ_NEED_WAKEUP too. Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22io_uring: fix race condition reading SQ entriesStefan Bühler
A read memory barrier is required between reading SQ tail and reading the actual data belonging to the SQ entry. Userspace needs a matching write barrier between writing SQ entries and updating SQ tail (using smp_store_release to update tail will do). Signed-off-by: Stefan Bühler <source@stbuehler.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22io_uring: fail io_uring_register(2) on a dying io_uring instanceJens Axboe
If we have multiple threads doing io_uring_register(2) on an io_uring fd, then we can potentially try and kill the percpu reference while someone else has already killed it. Prevent this race by failing io_uring_register(2) if the ref is marked dying. This is safe since we're inside the io_uring mutex. Fixes: b19062a56726 ("io_uring: fix possible deadlock between io_uring_{enter,register}") Reported-by: syzbot <syzbot+10d25e23199614b7721f@syzkaller.appspotmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-20Merge tag 'for-linus-20190420' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A set of small fixes that should go into this series. This contains: - Removal of unused queue member (Hou) - Overflow bvec fix (Ming) - Various little io_uring tweaks (me) - kthread parking - Only call cpu_possible() for verified CPU - Drop unused 'file' argument to io_file_put() - io_uring_enter vs io_uring_register deadlock fix - CQ overflow fix - BFQ internal depth update fix (me)" * tag 'for-linus-20190420' of git://git.kernel.dk/linux-block: block: make sure that bvec length can't be overflow block: kill all_q_node in request_queue io_uring: fix CQ overflow condition io_uring: fix possible deadlock between io_uring_{enter,register} io_uring: drop io_file_put() 'file' argument bfq: update internal depth state when queue depth changes io_uring: only test SQPOLL cpu after we've verified it io_uring: park SQPOLL thread if it's percpu
2019-04-19coredump: fix race condition between mmget_not_zero()/get_task_mm() and core ↵Andrea Arcangeli
dumping The core dumping code has always run without holding the mmap_sem for writing, despite that is the only way to ensure that the entire vma layout will not change from under it. Only using some signal serialization on the processes belonging to the mm is not nearly enough. This was pointed out earlier. For example in Hugh's post from Jul 2017: https://lkml.kernel.org/r/alpine.LSU.2.11.1707191716030.2055@eggly.anvils "Not strictly relevant here, but a related note: I was very surprised to discover, only quite recently, how handle_mm_fault() may be called without down_read(mmap_sem) - when core dumping. That seems a misguided optimization to me, which would also be nice to correct" In particular because the growsdown and growsup can move the vm_start/vm_end the various loops the core dump does around the vma will not be consistent if page faults can happen concurrently. Pretty much all users calling mmget_not_zero()/get_task_mm() and then taking the mmap_sem had the potential to introduce unexpected side effects in the core dumping code. Adding mmap_sem for writing around the ->core_dump invocation is a viable long term fix, but it requires removing all copy user and page faults and to replace them with get_dump_page() for all binary formats which is not suitable as a short term fix. For the time being this solution manually covers the places that can confuse the core dump either by altering the vma layout or the vma flags while it runs. Once ->core_dump runs under mmap_sem for writing the function mmget_still_valid() can be dropped. Allowing mmap_sem protected sections to run in parallel with the coredump provides some minor parallelism advantage to the swapoff code (which seems to be safe enough by never mangling any vma field and can keep doing swapins in parallel to the core dumping) and to some other corner case. In order to facilitate the backporting I added "Fixes: 86039bd3b4e6" however the side effect of this same race condition in /proc/pid/mem should be reproducible since before 2.6.12-rc2 so I couldn't add any other "Fixes:" because there's no hash beyond the git genesis commit. Because find_extend_vma() is the only location outside of the process context that could modify the "mm" structures under mmap_sem for reading, by adding the mmget_still_valid() check to it, all other cases that take the mmap_sem for reading don't need the new check after mmget_not_zero()/get_task_mm(). The expand_stack() in page fault context also doesn't need the new check, because all tasks under core dumping are frozen. Link: http://lkml.kernel.org/r/20190325224949.11068-1-aarcange@redhat.com Fixes: 86039bd3b4e6 ("userfaultfd: add new syscall to provide memory externalization") Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Jann Horn <jannh@google.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Jann Horn <jannh@google.com> Acked-by: Jason Gunthorpe <jgg@mellanox.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-18Merge tag 'afs-fixes-20190413' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull AFS fixes from David Howells: - Stop using the deprecated get_seconds(). - Don't make tracepoint strings const as the section they go in isn't read-only. - Differentiate failure due to unmarshalling from other failure cases. We shouldn't abort with RXGEN_CC/SS_UNMARSHAL if it's not due to unmarshalling. - Add a missing unlock_page(). - Fix the interaction between receiving a notification from a server that it has invalidated all outstanding callback promises and a client call that we're in the middle of making that will get a new promise. * tag 'afs-fixes-20190413' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: afs: Fix in-progess ops to ignore server-level callback invalidation afs: Unlock pages for __pagevec_release() afs: Differentiate abort due to unmarshalling from other errors afs: Avoid section confusion in CM_NAME afs: avoid deprecated get_seconds()
2019-04-17Merge tag '5.1-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull smb3 fixes from Steve French: "Five small SMB3 fixes, all also for stable - an important fix for an oplock (lease) bug, a handle leak, and three bugs spotted by KASAN" * tag '5.1-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: CIFS: keep FileInfo handle live during oplock break cifs: fix handle leak in smb2_query_symlink() cifs: Fix lease buffer length error cifs: Fix use-after-free in SMB2_read cifs: Fix use-after-free in SMB2_write
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