KCSAN: data-race in bdev_disk_changed / bdev_set_nr

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in bdev_disk_changed / bdev_set_nr_sectors (2) block				2	73d	93d	0/26	auto-obsoleted due to no activity on 2024/03/31 19:37

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BUG: KCSAN: data-race in bdev_disk_changed / bdev_set_nr_sectors

write to 0xffff8881005b0008 of 8 bytes by task 9310 on cpu 0:
 bdev_set_nr_sectors+0x50/0x70 block/bdev.c:422
 set_capacity block/genhd.c:61 [inline]
 set_capacity_and_notify+0x6e/0x170 block/genhd.c:74
 loop_set_size+0x2e/0x70 drivers/block/loop.c:237
 loop_configure+0xaf9/0xca0 drivers/block/loop.c:1100
 lo_ioctl+0x682/0x12e0
 blkdev_ioctl+0x375/0x460 block/ioctl.c:630
 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:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881005b0008 of 8 bytes by task 9287 on cpu 1:
 bdev_nr_sectors include/linux/blkdev.h:767 [inline]
 get_capacity include/linux/blkdev.h:777 [inline]
 bdev_disk_changed+0x1db/0xbd0 block/partitions/core.c:684
 blkdev_get_whole+0x227/0x240 block/bdev.c:653
 blkdev_get_by_dev+0x236/0x390 block/bdev.c:795
 blkdev_open+0xf7/0x1e0 block/fops.c:589
 do_dentry_open+0x5c3/0xae0 fs/open.c:929
 vfs_open+0x4a/0x50 fs/open.c:1063
 do_open fs/namei.c:3639 [inline]
 path_openat+0x17f2/0x1d10 fs/namei.c:3796
 do_filp_open+0xf6/0x200 fs/namei.c:3823
 do_sys_openat2+0xab/0x110 fs/open.c:1422
 do_sys_open fs/open.c:1437 [inline]
 __do_sys_openat fs/open.c:1453 [inline]
 __se_sys_openat fs/open.c:1448 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1448
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000000 -> 0x00000000000000a4

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9287 Comm: udevd Not tainted 6.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
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