From: Lee Jones <lee.jones@xxxxxxxxxx> This reverts commit 88dbd085a51ec78c83dde79ad63bca8aa4272a9d. Causes the following Syzkaller reported issue: BUG: kernel NULL pointer dereference, address: 0000000000000010 PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 546 Comm: syz-executor631 Tainted: G B 5.10.76-syzkaller-01178-g4944ec82ebb9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_atomic_try_cmpxchg syzkaller/managers/android-5-10/kernel/./arch/x86/include/asm/atomic.h:202 [inline] RIP: 0010:atomic_try_cmpxchg_acquire syzkaller/managers/android-5-10/kernel/./include/asm-generic/atomic-instrumented.h:707 [inline] RIP: 0010:queued_spin_lock syzkaller/managers/android-5-10/kernel/./include/asm-generic/qspinlock.h:82 [inline] RIP: 0010:do_raw_spin_lock_flags syzkaller/managers/android-5-10/kernel/./include/linux/spinlock.h:195 [inline] RIP: 0010:__raw_spin_lock_irqsave syzkaller/managers/android-5-10/kernel/./include/linux/spinlock_api_smp.h:119 [inline] RIP: 0010:_raw_spin_lock_irqsave+0x10d/0x210 syzkaller/managers/android-5-10/kernel/kernel/locking/spinlock.c:159 Code: 00 00 00 e8 d5 29 09 fd 4c 89 e7 be 04 00 00 00 e8 c8 29 09 fd 42 8a 04 3b 84 c0 0f 85 be 00 00 00 8b 44 24 40 b9 01 00 00 00 <f0> 41 0f b1 4d 00 75 45 48 c7 44 24 20 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc90000f174e0 EFLAGS: 00010097 RAX: 0000000000000000 RBX: 1ffff920001e2ea4 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000f17520 RBP: ffffc90000f175b0 R08: dffffc0000000000 R09: 0000000000000003 R10: fffff520001e2ea5 R11: 0000000000000004 R12: ffffc90000f17520 R13: 0000000000000010 R14: 1ffff920001e2ea0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 000000000640f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: prepare_to_wait+0x9c/0x290 syzkaller/managers/android-5-10/kernel/kernel/sched/wait.c:248 io_uring_cancel_files syzkaller/managers/android-5-10/kernel/fs/io_uring.c:8690 [inline] io_uring_cancel_task_requests+0x16a9/0x1ed0 syzkaller/managers/android-5-10/kernel/fs/io_uring.c:8760 io_uring_flush+0x170/0x6d0 syzkaller/managers/android-5-10/kernel/fs/io_uring.c:8923 filp_close+0xb0/0x150 syzkaller/managers/android-5-10/kernel/fs/open.c:1319 close_files syzkaller/managers/android-5-10/kernel/fs/file.c:401 [inline] put_files_struct+0x1d4/0x350 syzkaller/managers/android-5-10/kernel/fs/file.c:429 exit_files+0x80/0xa0 syzkaller/managers/android-5-10/kernel/fs/file.c:458 do_exit+0x6d9/0x23a0 syzkaller/managers/android-5-10/kernel/kernel/exit.c:808 do_group_exit+0x16a/0x2d0 syzkaller/managers/android-5-10/kernel/kernel/exit.c:910 get_signal+0x133e/0x1f80 syzkaller/managers/android-5-10/kernel/kernel/signal.c:2790 arch_do_signal+0x8d/0x620 syzkaller/managers/android-5-10/kernel/arch/x86/kernel/signal.c:805 exit_to_user_mode_loop syzkaller/managers/android-5-10/kernel/kernel/entry/common.c:161 [inline] exit_to_user_mode_prepare+0xaa/0xe0 syzkaller/managers/android-5-10/kernel/kernel/entry/common.c:191 syscall_exit_to_user_mode+0x24/0x40 syzkaller/managers/android-5-10/kernel/kernel/entry/common.c:266 do_syscall_64+0x3d/0x70 syzkaller/managers/android-5-10/kernel/arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fc6d1589a89 Code: Unable to access opcode bytes at RIP 0x7fc6d1589a5f. RSP: 002b:00007ffd2b5da728 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffdfc RBX: 0000000000005193 RCX: 00007fc6d1589a89 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc6d161142c RBP: 0000000000000032 R08: 00007ffd2b5eb0b8 R09: 0000000000000000 R10: 00007ffd2b5da750 R11: 0000000000000246 R12: 00007fc6d161142c R13: 00007ffd2b5da750 R14: 00007ffd2b5da770 R15: 0000000000000000 Modules linked in: CR2: 0000000000000010 ---[ end trace fe8044f7dc4d8d65 ]--- RIP: 0010:arch_atomic_try_cmpxchg syzkaller/managers/android-5-10/kernel/./arch/x86/include/asm/atomic.h:202 [inline] RIP: 0010:atomic_try_cmpxchg_acquire syzkaller/managers/android-5-10/kernel/./include/asm-generic/atomic-instrumented.h:707 [inline] RIP: 0010:queued_spin_lock syzkaller/managers/android-5-10/kernel/./include/asm-generic/qspinlock.h:82 [inline] RIP: 0010:do_raw_spin_lock_flags syzkaller/managers/android-5-10/kernel/./include/linux/spinlock.h:195 [inline] RIP: 0010:__raw_spin_lock_irqsave syzkaller/managers/android-5-10/kernel/./include/linux/spinlock_api_smp.h:119 [inline] RIP: 0010:_raw_spin_lock_irqsave+0x10d/0x210 syzkaller/managers/android-5-10/kernel/kernel/locking/spinlock.c:159 Code: 00 00 00 e8 d5 29 09 fd 4c 89 e7 be 04 00 00 00 e8 c8 29 09 fd 42 8a 04 3b 84 c0 0f 85 be 00 00 00 8b 44 24 40 b9 01 00 00 00 <f0> 41 0f b1 4d 00 75 45 48 c7 44 24 20 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc90000f174e0 EFLAGS: 00010097 RAX: 0000000000000000 RBX: 1ffff920001e2ea4 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000f17520 RBP: ffffc90000f175b0 R08: dffffc0000000000 R09: 0000000000000003 R10: fffff520001e2ea5 R11: 0000000000000004 R12: ffffc90000f17520 R13: 0000000000000010 R14: 1ffff920001e2ea0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 000000000640f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 00 add %al,(%rax) 2: e8 d5 29 09 fd callq 0xfd0929dc 7: 4c 89 e7 mov %r12,%rdi a: be 04 00 00 00 mov $0x4,%esi f: e8 c8 29 09 fd callq 0xfd0929dc 14: 42 8a 04 3b mov (%rbx,%r15,1),%al 18: 84 c0 test %al,%al 1a: 0f 85 be 00 00 00 jne 0xde 20: 8b 44 24 40 mov 0x40(%rsp),%eax 24: b9 01 00 00 00 mov $0x1,%ecx * 29: f0 41 0f b1 4d 00 lock cmpxchg %ecx,0x0(%r13) <-- trapping instruction 2f: 75 45 jne 0x76 31: 48 c7 44 24 20 0e 36 movq $0x45e0360e,0x20(%rsp) 38: e0 45 3a: 4b rex.WXB 3b: c7 .byte 0xc7 3c: 04 37 add $0x37,%al Link: https://syzkaller.appspot.com/bug?extid=b0003676644cf0d6acc4 Reported-by: syzbot+b0003676644cf0d6acc4@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/io_uring.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8759,9 +8759,10 @@ static void io_uring_cancel_task_request io_cancel_defer_files(ctx, task, files); io_cqring_overflow_flush(ctx, true, task, files); - io_uring_cancel_files(ctx, task, files); if (!files) __io_uring_cancel_task_requests(ctx, task); + else + io_uring_cancel_files(ctx, task, files); if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { atomic_dec(&task->io_uring->in_idle);
