bisecting cause commit starting from 75887e881b19c903d34b7cc33e7e6188679d9752 building syzkaller on 6a383ecfb767c80c9fa63c7708b25e568a4ebfec testing commit 75887e881b19c903d34b7cc33e7e6188679d9752 with gcc (GCC) 10.2.1 20210217 kernel signature: 4cc559c60d91f7bcd6229ac68e9089abbc1ca1d731c97e5645928ee5ae2edaec all runs: crashed: KASAN: use-after-free Read in nfc_llcp_sock_unlink testing release v5.11 testing commit f40ddce88593482919761f74910f42f4b84c004b with gcc (GCC) 10.2.1 20210217 kernel signature: 0060f998cf503ac1654a9c4262c8927768d9a752547f1a416fab09d8bbd9070a all runs: OK # git bisect start 75887e881b19c903d34b7cc33e7e6188679d9752 f40ddce88593482919761f74910f42f4b84c004b Bisecting: 7294 revisions left to test after this (roughly 13 steps) [a864e8f159b13babf552aff14a5fbe11abc017e4] ALSA: hda: intel-nhlt: verify config type testing commit a864e8f159b13babf552aff14a5fbe11abc017e4 with gcc (GCC) 10.2.1 20210217 kernel signature: db7c4730c8a54777b660724b0df6ecf5057fa54b8ed855537f6dcd49b0eaf219 run #0: crashed: WARNING in kvm_wait run #1: crashed: WARNING in kvm_wait run #2: crashed: WARNING in kvm_wait run #3: crashed: WARNING in kvm_wait run #4: OK run #5: crashed: WARNING in kvm_wait run #6: boot failed: WARNING in kvm_wait run #7: boot failed: WARNING in kvm_wait run #8: boot failed: WARNING in kvm_wait run #9: boot failed: WARNING in kvm_wait # git bisect bad a864e8f159b13babf552aff14a5fbe11abc017e4 Bisecting: 2929 revisions left to test after this (roughly 12 steps) [e4286926abbbaab9b047c8bc25cae78ec990928f] Merge tag 'tty-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty testing commit e4286926abbbaab9b047c8bc25cae78ec990928f with gcc (GCC) 10.2.1 20210217 kernel signature: a665cf6fdec9d7b19a33666de345c4aafe3300dceaf1b2821458ba12a9be2b6c all runs: OK # git bisect good e4286926abbbaab9b047c8bc25cae78ec990928f Bisecting: 1417 revisions left to test after this (roughly 11 steps) [d089f48fba28db14d0fe7753248f2575a9ddfc73] Merge tag 'core-rcu-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit d089f48fba28db14d0fe7753248f2575a9ddfc73 with gcc (GCC) 10.2.1 20210217 kernel signature: 4684430b97c9d93cf4e44ba1de789897bd72097e4f1cde7465a7d4dd4d49d569 all runs: OK # git bisect good d089f48fba28db14d0fe7753248f2575a9ddfc73 Bisecting: 737 revisions left to test after this (roughly 10 steps) [66f73fb3facd42d0a7c899d7f4c712332b28499a] Merge tag 'for-linus-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs testing commit 66f73fb3facd42d0a7c899d7f4c712332b28499a with gcc (GCC) 10.2.1 20210217 kernel signature: 9b15ab62a4bb2169536f460f8a315dc3727172257f7e87ea84776f705f86b404 run #0: crashed: WARNING in kvm_wait run #1: crashed: WARNING in kvm_wait run #2: crashed: WARNING in kvm_wait run #3: crashed: WARNING in kvm_wait run #4: crashed: WARNING in kvm_wait run #5: crashed: WARNING in kvm_wait run #6: crashed: WARNING in kvm_wait run #7: OK run #8: boot failed: WARNING in kvm_wait run #9: boot failed: WARNING in kvm_wait # git bisect bad 66f73fb3facd42d0a7c899d7f4c712332b28499a Bisecting: 355 revisions left to test after this (roughly 8 steps) [08179b47e1fdf288e5d59f90e5ce31513bb019c3] Merge branch 'parisc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux testing commit 08179b47e1fdf288e5d59f90e5ce31513bb019c3 with gcc (GCC) 10.2.1 20210217 kernel signature: 4bd8b2ec5b6867fc4a19d98d4525b5b9a650ecd22c881cf02dd740d5c432b0d6 run #0: crashed: WARNING in kvm_wait run #1: crashed: WARNING in kvm_wait run #2: crashed: WARNING in kvm_wait run #3: OK run #4: OK run #5: OK run #6: OK run #7: boot failed: WARNING in kvm_wait run #8: boot failed: WARNING in kvm_wait run #9: boot failed: WARNING in kvm_wait reproducer seems to be flaky # git bisect bad 08179b47e1fdf288e5d59f90e5ce31513bb019c3 Bisecting: 209 revisions left to test after this (roughly 7 steps) [4a037ad5d115b2cc79a5071a7854475f365476fa] Merge tag 'for-linus-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip testing commit 4a037ad5d115b2cc79a5071a7854475f365476fa with gcc (GCC) 10.2.1 20210217 kernel signature: 622f41877dc7ef3e8d9e3e5146e880e00904404ceb118bf17bc5ced4f3da2b2d run #0: crashed: WARNING in kvm_wait run #1: crashed: WARNING in kvm_wait run #2: crashed: WARNING in kvm_wait run #3: crashed: WARNING in kvm_wait run #4: crashed: WARNING in kvm_wait run #5: crashed: WARNING in kvm_wait run #6: crashed: WARNING in kvm_wait run #7: crashed: WARNING in kvm_wait run #8: crashed: WARNING in kvm_wait run #9: crashed: WARNING in kvm_wait run #10: crashed: WARNING in kvm_wait run #11: crashed: WARNING in kvm_wait run #12: OK run #13: OK run #14: OK run #15: OK run #16: OK run #17: boot failed: WARNING in kvm_wait run #18: boot failed: WARNING in kvm_wait run #19: boot failed: WARNING in kvm_wait # git bisect bad 4a037ad5d115b2cc79a5071a7854475f365476fa Bisecting: 61 revisions left to test after this (roughly 6 steps) [c5e6fc08feb2b88dc5dac2f3c817e1c2a4cafda4] sched,x86: Allow !PREEMPT_DYNAMIC testing commit c5e6fc08feb2b88dc5dac2f3c817e1c2a4cafda4 with gcc (GCC) 10.2.1 20210217 kernel signature: 54cb92593d5b1c9fdda48873212c9a2537b55369f0597920c7fbe9a3444a2c4a all runs: OK # git bisect good c5e6fc08feb2b88dc5dac2f3c817e1c2a4cafda4 Bisecting: 33 revisions left to test after this (roughly 5 steps) [9eef02334505411667a7b51a8f349f8c6c4f3b66] Merge tag 'locking-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit 9eef02334505411667a7b51a8f349f8c6c4f3b66 with gcc (GCC) 10.2.1 20210217 kernel signature: 1f2f5873967112007b01717e3d5175ec20b85320a28c0f54ff9b597941b97bfd run #0: crashed: WARNING in kvm_wait run #1: crashed: WARNING in kvm_wait run #2: crashed: WARNING in kvm_wait run #3: crashed: WARNING in kvm_wait run #4: crashed: WARNING in kvm_wait run #5: crashed: WARNING in kvm_wait run #6: crashed: WARNING in kvm_wait run #7: crashed: WARNING in kvm_wait run #8: crashed: WARNING in kvm_wait run #9: crashed: WARNING in kvm_wait run #10: crashed: WARNING in kvm_wait run #11: OK run #12: OK run #13: crashed: WARNING in kvm_wait run #14: OK run #15: boot failed: WARNING in kvm_wait run #16: boot failed: WARNING in kvm_wait run #17: boot failed: WARNING in kvm_wait run #18: boot failed: WARNING in kvm_wait run #19: boot failed: WARNING in kvm_wait # git bisect bad 9eef02334505411667a7b51a8f349f8c6c4f3b66 Bisecting: 13 revisions left to test after this (roughly 4 steps) [442187f3c2de40bab13b8f9751b37925bede73b0] locking/rwsem: Remove empty rwsem.h testing commit 442187f3c2de40bab13b8f9751b37925bede73b0 with gcc (GCC) 10.2.1 20210217 kernel signature: 0dcba72778d8bb5919a4948e3eae41dde0b9204d48732d2748816a7472f448d3 run #0: crashed: WARNING in kvm_wait run #1: crashed: WARNING in kvm_wait run #2: crashed: WARNING in kvm_wait run #3: crashed: WARNING in kvm_wait run #4: crashed: WARNING in kvm_wait run #5: crashed: WARNING in kvm_wait run #6: crashed: WARNING in kvm_wait run #7: crashed: WARNING in kvm_wait run #8: crashed: WARNING in kvm_wait run #9: crashed: WARNING in kvm_wait run #10: crashed: WARNING in kvm_wait run #11: crashed: WARNING in kvm_wait run #12: crashed: WARNING in kvm_wait run #13: crashed: WARNING in kvm_wait run #14: OK run #15: OK run #16: crashed: WARNING in kvm_wait run #17: OK run #18: OK run #19: OK # git bisect bad 442187f3c2de40bab13b8f9751b37925bede73b0 Bisecting: 6 revisions left to test after this (roughly 3 steps) [7e923e6a3ceb877497dd9ee70d71fa33b94f332b] locking/selftests: Add local_lock inversion tests testing commit 7e923e6a3ceb877497dd9ee70d71fa33b94f332b with gcc (GCC) 10.2.1 20210217 kernel signature: 4a641002a53ce9ea2bc008382f14d214d80c76a51e3d3f6c3abd3b744af957cd all runs: OK # git bisect good 7e923e6a3ceb877497dd9ee70d71fa33b94f332b Bisecting: 3 revisions left to test after this (roughly 2 steps) [997acaf6b4b59c6a9c259740312a69ea549cc684] lockdep: report broken irq restoration testing commit 997acaf6b4b59c6a9c259740312a69ea549cc684 with gcc (GCC) 10.2.1 20210217 kernel signature: 669982df11263e22180245087d40ef0243ca23d7e4357987520e195942d81f1c run #0: crashed: WARNING in kvm_wait run #1: crashed: WARNING in kvm_wait run #2: crashed: WARNING in kvm_wait run #3: crashed: WARNING in kvm_wait run #4: crashed: WARNING in kvm_wait run #5: crashed: WARNING in kvm_wait run #6: crashed: WARNING in kvm_wait run #7: crashed: WARNING in kvm_wait run #8: crashed: WARNING in kvm_wait run #9: crashed: WARNING in kvm_wait run #10: crashed: WARNING in kvm_wait run #11: crashed: WARNING in kvm_wait run #12: crashed: WARNING in kvm_wait run #13: OK run #14: OK run #15: boot failed: WARNING in kvm_wait run #16: boot failed: WARNING in kvm_wait run #17: boot failed: WARNING in kvm_wait run #18: boot failed: WARNING in kvm_wait run #19: boot failed: WARNING in kvm_wait # git bisect bad 997acaf6b4b59c6a9c259740312a69ea549cc684 Bisecting: 0 revisions left to test after this (roughly 1 step) [2f0df49c89acaa58571d509830bc481250699885] jump_label: Do not profile branch annotations testing commit 2f0df49c89acaa58571d509830bc481250699885 with gcc (GCC) 10.2.1 20210217 kernel signature: 4a641002a53ce9ea2bc008382f14d214d80c76a51e3d3f6c3abd3b744af957cd all runs: OK # git bisect good 2f0df49c89acaa58571d509830bc481250699885 997acaf6b4b59c6a9c259740312a69ea549cc684 is the first bad commit commit 997acaf6b4b59c6a9c259740312a69ea549cc684 Author: Mark Rutland Date: Mon Jan 11 15:37:07 2021 +0000 lockdep: report broken irq restoration We generally expect local_irq_save() and local_irq_restore() to be paired and sanely nested, and so local_irq_restore() expects to be called with irqs disabled. Thus, within local_irq_restore() we only trace irq flag changes when unmasking irqs. This means that a sequence such as: | local_irq_disable(); | local_irq_save(flags); | local_irq_enable(); | local_irq_restore(flags); ... is liable to break things, as the local_irq_restore() would mask irqs without tracing this change. Similar problems may exist for architectures whose arch_irq_restore() function depends on being called with irqs disabled. We don't consider such sequences to be a good idea, so let's define those as forbidden, and add tooling to detect such broken cases. This patch adds debug code to WARN() when raw_local_irq_restore() is called with irqs enabled. As raw_local_irq_restore() is expected to pair with raw_local_irq_save(), it should never be called with irqs enabled. To avoid the possibility of circular header dependencies between irqflags.h and bug.h, the warning is handled in a separate C file. The new code is all conditional on a new CONFIG_DEBUG_IRQFLAGS symbol which is independent of CONFIG_TRACE_IRQFLAGS. As noted above such cases will confuse lockdep, so CONFIG_DEBUG_LOCKDEP now selects CONFIG_DEBUG_IRQFLAGS. Signed-off-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20210111153707.10071-1-mark.rutland@arm.com include/linux/irqflags.h | 12 ++++++++++++ kernel/locking/Makefile | 1 + kernel/locking/irqflag-debug.c | 11 +++++++++++ lib/Kconfig.debug | 8 ++++++++ 4 files changed, 32 insertions(+) create mode 100644 kernel/locking/irqflag-debug.c culprit signature: 669982df11263e22180245087d40ef0243ca23d7e4357987520e195942d81f1c parent signature: 4a641002a53ce9ea2bc008382f14d214d80c76a51e3d3f6c3abd3b744af957cd Reproducer flagged being flaky revisions tested: 14, total time: 3h49m40.631669314s (build: 1h36m18.058058845s, test: 2h11m28.279199914s) first bad commit: 997acaf6b4b59c6a9c259740312a69ea549cc684 lockdep: report broken irq restoration recipients (to): ["linux-kernel@vger.kernel.org" "mark.rutland@arm.com" "mingo@redhat.com" "peterz@infradead.org" "peterz@infradead.org" "will@kernel.org"] recipients (cc): ["akpm@linux-foundation.org" "masahiroy@kernel.org" "rafael.j.wysocki@intel.com" "rostedt@goodmis.org" "tglx@linutronix.de"] crash: WARNING in kvm_wait ------------[ cut here ]------------ raw_local_irq_restore() called with IRQs enabled WARNING: CPU: 1 PID: 8797 at kernel/locking/irqflag-debug.c:9 warn_bogus_irq_restore kernel/locking/irqflag-debug.c:9 [inline] WARNING: CPU: 1 PID: 8797 at kernel/locking/irqflag-debug.c:9 warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:7 Modules linked in: CPU: 1 PID: 8797 Comm: syz-executor.0 Not tainted 5.11.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:warn_bogus_irq_restore kernel/locking/irqflag-debug.c:9 [inline] RIP: 0010:warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:7 Code: 51 00 e9 3f fe ff ff cc cc cc cc cc cc 80 3d 60 bf cf 0a 00 74 01 c3 48 c7 c7 60 f5 8a 88 c6 05 4f bf cf 0a 01 e8 17 11 a7 06 <0f> 0b c3 48 c7 c0 a0 06 4f 8e 53 48 89 fb 48 ba 00 00 00 00 00 fc RSP: 0018:ffffc900016cf9f8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff888020a77040 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000004 RDI: fffff520002d9f31 RBP: 0000000000000246 R08: 0000000000000001 R09: ffff8880b9f2015b R10: ffffed10173e402b R11: 0000000000000001 R12: 0000000000000003 R13: ffffed100414ee08 R14: 0000000000000001 R15: ffff8880b9f359c0 FS: 00000000033f2400(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd5c947ff8 CR3: 0000000023cd3000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kvm_wait arch/x86/kernel/kvm.c:860 [inline] kvm_wait+0xc3/0xe0 arch/x86/kernel/kvm.c:837 pv_wait arch/x86/include/asm/paravirt.h:564 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x8b8/0xb40 kernel/locking/qspinlock.c:508 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113 spin_lock include/linux/spinlock.h:354 [inline] ext4_lock_group fs/ext4/ext4.h:3379 [inline] __ext4_new_inode+0x2da2/0x44d0 fs/ext4/ialloc.c:1187 ext4_mkdir+0x298/0x910 fs/ext4/namei.c:2793 vfs_mkdir+0x413/0x660 fs/namei.c:3652 do_mkdirat+0x1eb/0x250 fs/namei.c:3675 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465567 Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd5c949368 EFLAGS: 00000202 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007ffd5c949400 RCX: 0000000000465567 RDX: 0000000000000000 RSI: 00000000000001ff RDI: 00007ffd5c949400 RBP: 00007ffd5c9493dc R08: 0000000000000000 R09: 0000000000000006 R10: 00007ffd5c949104 R11: 0000000000000202 R12: 0000000000000032 R13: 000000000005d8eb R14: 0000000000000004 R15: 00007ffd5c949440