* [syzbot] [block?] WARNING in blk_mq_start_request
@ 2023-11-07 7:29 syzbot
2023-11-08 2:46 ` [PATCH] null_blk: fix warning " Edward Adam Davis
0 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2023-11-07 7:29 UTC (permalink / raw)
To: axboe, linux-block, linux-kernel, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 4652b8e4f3ff Merge tag '6.7-rc-ksmbd-server-fixes' of git:..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=117a6ebb680000
kernel config: https://syzkaller.appspot.com/x/.config?x=5316ad879647e3c5
dashboard link: https://syzkaller.appspot.com/bug?extid=fcc47ba2476570cbbeb0
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13489af3680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=145c7d07680000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-4652b8e4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9c5be65b1bc8/vmlinux-4652b8e4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8799a4da0be5/bzImage-4652b8e4.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fcc47ba2476570cbbeb0@syzkaller.appspotmail.com
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffff489c59c
R13: 00007ffff489c5b0 R14: 00007ffff489c5f0 R15: 0000000000000003
</TASK>
------------[ cut here ]------------
WARNING: CPU: 3 PID: 5178 at block/blk-mq.c:1258 blk_mq_start_request+0x643/0x780 block/blk-mq.c:1258
Modules linked in:
CPU: 3 PID: 5178 Comm: syz-executor268 Not tainted 6.6.0-syzkaller-10396-g4652b8e4f3ff #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:blk_mq_start_request+0x643/0x780 block/blk-mq.c:1258
Code: 00 00 fc ff df 48 8d 7d 10 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 2f 01 00 00 48 89 df ff 55 10 e9 64 fc ff ff e8 1d 9c 44 fd <0f> 0b e9 f6 fa ff ff e8 11 9c 44 fd 0f 0b e9 06 fa ff ff e8 05 9c
RSP: 0018:ffffc900035ef298 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888018539e00 RCX: ffffffff8442db37
RDX: ffff888030114f00 RSI: ffffffff8442e043 RDI: 0000000000000005
RBP: ffff888018539e94 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888106a33350
R13: 0000000000000001 R14: ffff888018539f1d R15: ffff888018539f20
FS: 0000555555f00480(0000) GS:ffff88806b900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555f00788 CR3: 000000002238a000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
null_queue_rq+0x2e2/0x7a0 drivers/block/null_blk/main.c:1727
__blk_mq_issue_directly+0xe3/0x270 block/blk-mq.c:2578
blk_mq_request_issue_directly+0x120/0x190 block/blk-mq.c:2663
blk_mq_plug_issue_direct+0x19e/0x670 block/blk-mq.c:2684
blk_mq_flush_plug_list.part.0+0x16b6/0x1e90 block/blk-mq.c:2793
blk_mq_flush_plug_list+0x62/0x80 block/blk-mq.c:2770
__blk_flush_plug+0x2c0/0x430 block/blk-core.c:1142
blk_finish_plug block/blk-core.c:1166 [inline]
blk_finish_plug+0x54/0xa0 block/blk-core.c:1163
read_pages+0x69b/0xdb0 mm/readahead.c:183
page_cache_ra_unbounded+0x457/0x5e0 mm/readahead.c:269
do_page_cache_ra mm/readahead.c:299 [inline]
page_cache_ra_order+0x72b/0xa80 mm/readahead.c:546
ondemand_readahead+0x493/0x1130 mm/readahead.c:668
page_cache_sync_ra+0x174/0x1d0 mm/readahead.c:695
page_cache_sync_readahead.constprop.0+0xb2/0xf0 include/linux/pagemap.h:1293
cramfs_blkdev_read fs/cramfs/inode.c:218 [inline]
cramfs_read+0x33f/0xae0 fs/cramfs/inode.c:278
cramfs_read_super+0xbd/0x9b0 fs/cramfs/inode.c:522
cramfs_blkdev_fill_super+0x116/0x2f0 fs/cramfs/inode.c:622
get_tree_bdev+0x3b5/0x650 fs/super.c:1595
cramfs_get_tree fs/cramfs/inode.c:958 [inline]
cramfs_get_tree+0x40/0x50 fs/cramfs/inode.c:948
vfs_get_tree+0x8c/0x370 fs/super.c:1768
do_new_mount fs/namespace.c:3337 [inline]
path_mount+0x1492/0x1ed0 fs/namespace.c:3664
do_mount fs/namespace.c:3677 [inline]
__do_sys_mount fs/namespace.c:3886 [inline]
__se_sys_mount fs/namespace.c:3863 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:3863
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7feca35df9f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 1a 00 00 90 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffff489c548 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffff489c550 RCX: 00007feca35df9f9
RDX: 0000000020000040 RSI: 00000000200000c0 RDI: 0000000020000000
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000003134
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffff489c59c
R13: 00007ffff489c5b0 R14: 00007ffff489c5f0 R15: 0000000000000003
</TASK>
---
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^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH] null_blk: fix warning in blk_mq_start_request
2023-11-07 7:29 [syzbot] [block?] WARNING in blk_mq_start_request syzbot
@ 2023-11-08 2:46 ` Edward Adam Davis
2023-11-08 5:26 ` Bart Van Assche
2023-11-08 6:40 ` [PATCH] null_blk: " Chaitanya Kulkarni
0 siblings, 2 replies; 7+ messages in thread
From: Edward Adam Davis @ 2023-11-08 2:46 UTC (permalink / raw)
To: syzbot+fcc47ba2476570cbbeb0
Cc: axboe, linux-block, linux-kernel, syzkaller-bugs
Before call blk_mq_start_request() in null_queue_rq(), initialize rq->state to
MQ_RQ_IDLE.
Reported-and-tested-by: syzbot+fcc47ba2476570cbbeb0@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
drivers/block/null_blk/main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 22a3cf7f32e2..0726534a5a24 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1724,6 +1724,8 @@ static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
cmd->fake_timeout = should_timeout_request(rq) ||
blk_should_fake_timeout(rq->q);
+ if (READ_ONCE(rq->state))
+ WRITE_ONCE(rq->state, MQ_RQ_IDLE);
blk_mq_start_request(rq);
if (should_requeue_request(rq)) {
--
2.25.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH] null_blk: fix warning in blk_mq_start_request
2023-11-08 2:46 ` [PATCH] null_blk: fix warning " Edward Adam Davis
@ 2023-11-08 5:26 ` Bart Van Assche
2023-11-08 6:59 ` [PATCH V2] blk-mq: " Edward Adam Davis
2023-11-08 6:40 ` [PATCH] null_blk: " Chaitanya Kulkarni
1 sibling, 1 reply; 7+ messages in thread
From: Bart Van Assche @ 2023-11-08 5:26 UTC (permalink / raw)
To: Edward Adam Davis, syzbot+fcc47ba2476570cbbeb0
Cc: axboe, linux-block, linux-kernel, syzkaller-bugs
On 11/7/23 18:46, Edward Adam Davis wrote:
> Before call blk_mq_start_request() in null_queue_rq(), initialize rq->state to
> MQ_RQ_IDLE.
>
> Reported-and-tested-by: syzbot+fcc47ba2476570cbbeb0@syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
> drivers/block/null_blk/main.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
> index 22a3cf7f32e2..0726534a5a24 100644
> --- a/drivers/block/null_blk/main.c
> +++ b/drivers/block/null_blk/main.c
> @@ -1724,6 +1724,8 @@ static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
> cmd->fake_timeout = should_timeout_request(rq) ||
> blk_should_fake_timeout(rq->q);
>
> + if (READ_ONCE(rq->state))
> + WRITE_ONCE(rq->state, MQ_RQ_IDLE);
> blk_mq_start_request(rq);
>
> if (should_requeue_request(rq)) {
All code that changes rq->state should occur in the block layer
core. Block drivers must not modify rq->state directly.
Bart.
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH V2] blk-mq: fix warning in blk_mq_start_request
2023-11-08 5:26 ` Bart Van Assche
@ 2023-11-08 6:59 ` Edward Adam Davis
2023-11-08 7:26 ` Christoph Hellwig
0 siblings, 1 reply; 7+ messages in thread
From: Edward Adam Davis @ 2023-11-08 6:59 UTC (permalink / raw)
To: bvanassche
Cc: axboe, eadavis, linux-block, linux-kernel,
syzbot+fcc47ba2476570cbbeb0, syzkaller-bugs
Before call queue_rq(), initialize rq->state to MQ_RQ_IDLE.
Reported-and-tested-by: syzbot+fcc47ba2476570cbbeb0@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
block/blk-mq.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e2d11183f62e..26f2921cbc50 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2575,6 +2575,8 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
* Any other error (busy), just add it to our list as we
* previously would have done.
*/
+ if (READ_ONCE(rq->state))
+ WRITE_ONCE(rq->state, MQ_RQ_IDLE);
ret = q->mq_ops->queue_rq(hctx, &bd);
switch (ret) {
case BLK_STS_OK:
--
2.25.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH V2] blk-mq: fix warning in blk_mq_start_request
2023-11-08 6:59 ` [PATCH V2] blk-mq: " Edward Adam Davis
@ 2023-11-08 7:26 ` Christoph Hellwig
0 siblings, 0 replies; 7+ messages in thread
From: Christoph Hellwig @ 2023-11-08 7:26 UTC (permalink / raw)
To: Edward Adam Davis
Cc: bvanassche, axboe, linux-block, linux-kernel,
syzbot+fcc47ba2476570cbbeb0, syzkaller-bugs
On Wed, Nov 08, 2023 at 02:59:40PM +0800, Edward Adam Davis wrote:
> Before call queue_rq(), initialize rq->state to MQ_RQ_IDLE.
Request should never be able to be allocated if they aren't in
MQ_RQ_IDLE. So papering over it here is not the right fix, we need
to figure out got it ends up being marked free in the bitmap while
not idle.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] null_blk: fix warning in blk_mq_start_request
2023-11-08 2:46 ` [PATCH] null_blk: fix warning " Edward Adam Davis
2023-11-08 5:26 ` Bart Van Assche
@ 2023-11-08 6:40 ` Chaitanya Kulkarni
2023-11-08 7:07 ` Edward Adam Davis
1 sibling, 1 reply; 7+ messages in thread
From: Chaitanya Kulkarni @ 2023-11-08 6:40 UTC (permalink / raw)
To: Edward Adam Davis, syzbot+fcc47ba2476570cbbeb0
Cc: axboe, linux-block, linux-kernel, syzkaller-bugs
On 11/7/2023 6:46 PM, Edward Adam Davis wrote:
> Before call blk_mq_start_request() in null_queue_rq(), initialize rq->state to
> MQ_RQ_IDLE.
>
> Reported-and-tested-by: syzbot+fcc47ba2476570cbbeb0@syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
do you have the actual report from syzkaller ?
-ck
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2023-11-08 7:26 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-11-07 7:29 [syzbot] [block?] WARNING in blk_mq_start_request syzbot
2023-11-08 2:46 ` [PATCH] null_blk: fix warning " Edward Adam Davis
2023-11-08 5:26 ` Bart Van Assche
2023-11-08 6:59 ` [PATCH V2] blk-mq: " Edward Adam Davis
2023-11-08 7:26 ` Christoph Hellwig
2023-11-08 6:40 ` [PATCH] null_blk: " Chaitanya Kulkarni
2023-11-08 7:07 ` Edward Adam Davis
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