[moderation] [block?] KCSAN: data-race in bdev_set_nr_sectors / force_page_cache_ra (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0dd3ee311255 Linux 6.7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16db434de80000
kernel config: https://syzkaller.appspot.com/x/.config?x=1bb2daade28c90a5
dashboard link: https://syzkaller.appspot.com/bug?extid=cef0473d584b13e01615
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/b3bdaecbc4f5/disk-0dd3ee31.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6656b77ef58a/vmlinux-0dd3ee31.xz
kernel image: https://storage.googleapis.com/syzbot-assets/85fa7f08c720/bzImage-0dd3ee31.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cef047...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in bdev_set_nr_sectors / force_page_cache_ra

write to 0xffff8881004c4270 of 8 bytes by task 26693 on cpu 0:
i_size_write include/linux/fs.h:932 [inline]
bdev_set_nr_sectors+0x42/0x70 block/bdev.c:421
set_capacity block/genhd.c:61 [inline]
set_capacity_and_notify+0x6e/0x170 block/genhd.c:74
loop_set_size drivers/block/loop.c:237 [inline]
loop_set_status+0x397/0x550 drivers/block/loop.c:1303
lo_ioctl+0x892/0x12e0
blkdev_ioctl+0x375/0x460 block/ioctl.c:633
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xcf/0x140 fs/ioctl.c:857
__x64_sys_ioctl+0x43/0x50 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff8881004c4270 of 8 bytes by task 26711 on cpu 1:
i_size_read include/linux/fs.h:910 [inline]
do_page_cache_ra mm/readahead.c:286 [inline]
force_page_cache_ra+0x126/0x1d0 mm/readahead.c:330
force_page_cache_readahead mm/internal.h:130 [inline]
generic_fadvise+0x2c7/0x460 mm/fadvise.c:106
vfs_fadvise mm/fadvise.c:185 [inline]
ksys_fadvise64_64 mm/fadvise.c:199 [inline]
__do_sys_fadvise64 mm/fadvise.c:214 [inline]
__se_sys_fadvise64 mm/fadvise.c:212 [inline]
__x64_sys_fadvise64+0xcf/0x110 mm/fadvise.c:212
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000000007ffe00 -> 0x00000000007fb400

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26711 Comm: syz-executor.4 Not tainted 6.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.