diff options
author | Jens Axboe <axboe@kernel.dk> | 2019-11-13 09:09:23 -0700 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2019-11-13 09:11:36 -0700 |
commit | 15dff286d0e0087d4dcd7049911f179e4e4cfd94 (patch) | |
tree | 7123299a64f4c67309eaff6e73386e5ffa20709d | |
parent | 7c9e7f0fe0d8abf856a957c150c48778e75154c1 (diff) | |
download | linux-15dff286d0e0087d4dcd7049911f179e4e4cfd94.tar.bz2 |
io_uring: check for validity of ->rings in teardown
Normally the rings are always valid, the exception is if we failed to
allocate the rings at setup time. syzbot reports this:
RSP: 002b:00007ffd6e8aa078 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441229
RDX: 0000000000000002 RSI: 0000000020000140 RDI: 0000000000000d0d
RBP: 00007ffd6e8aa090 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8903 Comm: syz-executor410 Not tainted 5.4.0-rc7-next-20191113
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline]
RIP: 0010:__io_commit_cqring fs/io_uring.c:496 [inline]
RIP: 0010:io_commit_cqring+0x1e1/0xdb0 fs/io_uring.c:592
Code: 03 0f 8e df 09 00 00 48 8b 45 d0 4c 8d a3 c0 00 00 00 4c 89 e2 48 c1
ea 03 44 8b b8 c0 01 00 00 48 b8 00 00 00 00 00 fc ff df <0f> b6 14 02 4c
89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 61
RSP: 0018:ffff88808f51fc08 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff815abe4a
RDX: 0000000000000018 RSI: ffffffff81d168d5 RDI: ffff8880a9166100
RBP: ffff88808f51fc70 R08: 0000000000000004 R09: ffffed1011ea3f7d
R10: ffffed1011ea3f7c R11: 0000000000000003 R12: 00000000000000c0
R13: ffff8880a91661c0 R14: 1ffff1101522cc10 R15: 0000000000000000
FS: 0000000001e7a880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000140 CR3: 000000009a74c000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
io_cqring_overflow_flush+0x6b9/0xa90 fs/io_uring.c:673
io_ring_ctx_wait_and_kill+0x24f/0x7c0 fs/io_uring.c:4260
io_uring_create fs/io_uring.c:4600 [inline]
io_uring_setup+0x1256/0x1cc0 fs/io_uring.c:4626
__do_sys_io_uring_setup fs/io_uring.c:4639 [inline]
__se_sys_io_uring_setup fs/io_uring.c:4636 [inline]
__x64_sys_io_uring_setup+0x54/0x80 fs/io_uring.c:4636
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441229
Code: e8 5c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd6e8aa078 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441229
RDX: 0000000000000002 RSI: 0000000020000140 RDI: 0000000000000d0d
RBP: 00007ffd6e8aa090 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace b0f5b127a57f623f ]---
RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline]
RIP: 0010:__io_commit_cqring fs/io_uring.c:496 [inline]
RIP: 0010:io_commit_cqring+0x1e1/0xdb0 fs/io_uring.c:592
Code: 03 0f 8e df 09 00 00 48 8b 45 d0 4c 8d a3 c0 00 00 00 4c 89 e2 48 c1
ea 03 44 8b b8 c0 01 00 00 48 b8 00 00 00 00 00 fc ff df <0f> b6 14 02 4c
89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 61
RSP: 0018:ffff88808f51fc08 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff815abe4a
RDX: 0000000000000018 RSI: ffffffff81d168d5 RDI: ffff8880a9166100
RBP: ffff88808f51fc70 R08: 0000000000000004 R09: ffffed1011ea3f7d
R10: ffffed1011ea3f7c R11: 0000000000000003 R12: 00000000000000c0
R13: ffff8880a91661c0 R14: 1ffff1101522cc10 R15: 0000000000000000
FS: 0000000001e7a880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000140 CR3: 000000009a74c000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
which is exactly the case of failing to allocate the SQ/CQ rings, and
then entering shutdown. Check if the rings are valid before trying to
access them at shutdown time.
Reported-by: syzbot+21147d79607d724bd6f3@syzkaller.appspotmail.com
Fixes: 1d7bb1d50fb4 ("io_uring: add support for backlogged CQ ring")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r-- | fs/io_uring.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 247e5e1137a3..99822bf89924 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4265,7 +4265,9 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) io_wq_cancel_all(ctx->io_wq); io_iopoll_reap_events(ctx); - io_cqring_overflow_flush(ctx, true); + /* if we failed setting up the ctx, we might not have any rings */ + if (ctx->rings) + io_cqring_overflow_flush(ctx, true); wait_for_completion(&ctx->completions[0]); io_ring_ctx_free(ctx); } |