[PATCH v5.10.y 1/1] Revert "io_uring: reinforce cancel on flush during exit"
From: Lee Jones
Date: Tue Nov 02 2021 - 11:49:45 EST
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>
---
fs/io_uring.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0736487165da4..32bf80e0a3772 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8757,9 +8757,10 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
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);
--
2.33.1.1089.g2158813163f-goog