Hello,
syzbot found the following crash on:
HEAD commit: 766d004d mm, kcsan: Instrument SLAB free with ASSERT_EXCLU..
git tree:
https://github.com/google/ktsan.git kcsan
console output:
https://syzkaller.appspot.com/x/log.txt?x=13b29a81e00000
kernel config:
https://syzkaller.appspot.com/x/.config?x=b313b4492ea15bae
dashboard link:
https://syzkaller.appspot.com/bug?extid=b9914ed52d5b1d63f71d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [
ax...@kernel.dk linux...@vger.kernel.org linux-...@vger.kernel.org el...@google.com]
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by:
syzbot+b9914e...@syzkaller.appspotmail.com
==================================================================
BUG: KCSAN: data-race in blk_mq_free_request / blk_mq_free_request
write to 0xffffe8ffffd2ddc8 of 8 bytes by interrupt on cpu 1:
blk_mq_free_request+0x199/0x340 block/blk-mq.c:503
__blk_mq_end_request block/blk-mq.c:539 [inline]
blk_mq_end_request+0x2d0/0x2f0 block/blk-mq.c:548
end_cmd drivers/block/null_blk_main.c:648 [inline]
end_cmd+0xa4/0x190 drivers/block/null_blk_main.c:642
null_complete_rq+0x1f/0x30 drivers/block/null_blk_main.c:675
blk_done_softirq+0x1e6/0x250 block/blk-softirq.c:37
__do_softirq+0x118/0x34a kernel/softirq.c:292
run_ksoftirqd+0x41/0x60 kernel/softirq.c:603
smpboot_thread_fn+0x374/0x4a0 kernel/smpboot.c:165
kthread+0x1cb/0x1f0 kernel/kthread.c:255
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
read to 0xffffe8ffffd2ddc8 of 8 bytes by interrupt on cpu 0:
blk_mq_free_request+0x185/0x340 block/blk-mq.c:503
__blk_mq_end_request block/blk-mq.c:539 [inline]
blk_mq_end_request+0x2d0/0x2f0 block/blk-mq.c:548
end_cmd drivers/block/null_blk_main.c:648 [inline]
end_cmd+0xa4/0x190 drivers/block/null_blk_main.c:642
null_complete_rq+0x1f/0x30 drivers/block/null_blk_main.c:675
blk_done_softirq+0x1e6/0x250 block/blk-softirq.c:37
__do_softirq+0x118/0x34a kernel/softirq.c:292
run_ksoftirqd+0x41/0x60 kernel/softirq.c:603
smpboot_thread_fn+0x374/0x4a0 kernel/smpboot.c:165
kthread+0x1cb/0x1f0 kernel/kthread.c:255
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
---
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