[moderation] [block?] KCSAN: data-race in dd_insert_requests / ll_back_merge_fn (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e0cce98fe279 Merge tag 'tpmdd-next-6.10-rc2' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14420dec980000
kernel config: https://syzkaller.appspot.com/x/.config?x=b639694183430f97
dashboard link: https://syzkaller.appspot.com/bug?extid=3ec6eb59b8705e9a9eda
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ax...@kernel.dk linux...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d842c66d71ef/disk-e0cce98f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d6549d16a1a0/vmlinux-e0cce98f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fa3ddb2c67c0/bzImage-e0cce98f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3ec6eb...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in dd_insert_requests / ll_back_merge_fn

write to 0xffff888101f81250 of 8 bytes by task 2748 on cpu 0:
dd_insert_request block/mq-deadline.c:695 [inline]
dd_insert_requests+0x4b6/0x670 block/mq-deadline.c:724
blk_mq_dispatch_plug_list block/blk-mq.c:2749 [inline]
blk_mq_flush_plug_list+0x647/0xde0 block/blk-mq.c:2799
__blk_flush_plug+0x216/0x290 block/blk-core.c:1194
blk_finish_plug+0x48/0x70 block/blk-core.c:1221
jbd2_journal_commit_transaction+0x1bc5/0x33e0 fs/jbd2/commit.c:794
kjournald2+0x243/0x430 fs/jbd2/journal.c:201
kthread+0x1d1/0x210 kernel/kthread.c:389
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff888101f81250 of 8 bytes by task 27893 on cpu 1:
req_set_nomerge block/blk.h:374 [inline]
ll_back_merge_fn+0x297/0x480 block/blk-merge.c:644
bio_attempt_back_merge+0x5c/0x520 block/blk-merge.c:983
blk_attempt_bio_merge+0x44f/0x490 block/blk-merge.c:1080
blk_attempt_plug_merge+0xb5/0x100 block/blk-merge.c:1126
blk_mq_attempt_bio_merge block/blk-mq.c:2840 [inline]
blk_mq_submit_bio+0x597/0xd90 block/blk-mq.c:2977
__submit_bio+0xf2/0x470 block/blk-core.c:627
__submit_bio_noacct_mq block/blk-core.c:708 [inline]
submit_bio_noacct_nocheck+0x295/0x6e0 block/blk-core.c:737
submit_bio_noacct+0x6b9/0x870 block/blk-core.c:848
submit_bio+0x218/0x230 block/blk-core.c:890
swap_writepage_bdev_async mm/page_io.c:372 [inline]
__swap_writepage+0x612/0xc50 mm/page_io.c:390
swap_writepage+0xa9/0x160 mm/page_io.c:209
pageout mm/vmscan.c:660 [inline]
shrink_folio_list+0x194f/0x2560 mm/vmscan.c:1341
reclaim_folio_list+0x81/0x1e0 mm/vmscan.c:2125
reclaim_pages+0x215/0x270 mm/vmscan.c:2161
madvise_cold_or_pageout_pte_range+0xe43/0xec0 mm/madvise.c:550
walk_pmd_range mm/pagewalk.c:143 [inline]
walk_pud_range mm/pagewalk.c:221 [inline]
walk_p4d_range mm/pagewalk.c:256 [inline]
walk_pgd_range+0x807/0xee0 mm/pagewalk.c:293
__walk_page_range+0xc5/0x330 mm/pagewalk.c:395
walk_page_range+0x395/0x4e0 mm/pagewalk.c:521
madvise_pageout_page_range mm/madvise.c:609 [inline]
madvise_pageout mm/madvise.c:636 [inline]
madvise_vma_behavior mm/madvise.c:1042 [inline]
madvise_walk_vmas mm/madvise.c:1268 [inline]
do_madvise+0x1b09/0x2610 mm/madvise.c:1464
__do_sys_madvise mm/madvise.c:1481 [inline]
__se_sys_madvise mm/madvise.c:1479 [inline]
__x64_sys_madvise+0x61/0x70 mm/madvise.c:1479
x64_sys_call+0x285d/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:29
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff8881029d3400

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 27893 Comm: syz-executor.2 Tainted: G W 6.10.0-rc1-syzkaller-00021-ge0cce98fe279 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================


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