syzbot


KCSAN: data-race in _copy_to_iter / fat_set_state (9)

Status: moderation: reported on 2024/09/22 23:03
Subsystems: exfat
[Documentation on labels]
Reported-by: syzbot+2b81a3bf21e02f911a09@syzkaller.appspotmail.com
First crash: 5d16h, last: 5d16h
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in _copy_to_iter / fat_set_state (6) exfat 4 344d 365d 0/28 auto-obsoleted due to no activity on 2023/11/24 07:27
upstream KCSAN: data-race in _copy_to_iter / fat_set_state (5) exfat 1 410d 410d 0/28 auto-obsoleted due to no activity on 2023/09/19 09:04
upstream KCSAN: data-race in _copy_to_iter / fat_set_state (4) exfat 1 467d 467d 0/28 auto-obsoleted due to no activity on 2023/07/24 15:00
upstream KCSAN: data-race in _copy_to_iter / fat_set_state (7) exfat 6 211d 270d 0/28 auto-obsoleted due to no activity on 2024/04/05 03:03
upstream KCSAN: data-race in _copy_to_iter / fat_set_state (8) exfat 2 83d 117d 0/28 auto-obsoleted due to no activity on 2024/08/11 01:41
upstream KCSAN: data-race in _copy_to_iter / fat_set_state (3) exfat 1 560d 560d 0/28 auto-obsoleted due to no activity on 2023/04/29 03:39
upstream KCSAN: data-race in _copy_to_iter / fat_set_state (2) exfat 2 688d 715d 0/28 auto-obsoleted due to no activity on 2022/12/15 10:49
upstream KCSAN: data-race in _copy_to_iter / fat_set_state exfat 1 786d 786d 0/28 auto-closed as invalid on 2022/09/08 00:15

Sample crash report:
==================================================================
BUG: KCSAN: data-race in _copy_to_iter / fat_set_state

write to 0xffff88811e4b8041 of 1 bytes by task 11077 on cpu 0:
 fat_set_state+0x16e/0x1e0
 fat_fill_super+0x1798/0x1bf0 fs/fat/inode.c:1832
 vfat_fill_super+0x24/0x30 fs/fat/namei_vfat.c:1200
 get_tree_bdev+0x256/0x2e0 fs/super.c:1635
 vfat_get_tree+0x1c/0x30 fs/fat/namei_vfat.c:1205
 vfs_get_tree+0x56/0x1e0 fs/super.c:1800
 do_new_mount+0x227/0x690 fs/namespace.c:3507
 path_mount+0x49b/0xb30 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4055 [inline]
 __se_sys_mount+0x27c/0x2d0 fs/namespace.c:4032
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4032
 x64_sys_call+0x203e/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:166
 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

read to 0xffff88811e4b8000 of 1024 bytes by task 3961 on cpu 1:
 instrument_copy_to_user include/linux/instrumented.h:113 [inline]
 copy_to_user_iter lib/iov_iter.c:24 [inline]
 iterate_ubuf include/linux/iov_iter.h:30 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:300 [inline]
 iterate_and_advance include/linux/iov_iter.h:328 [inline]
 _copy_to_iter+0x126/0xd20 lib/iov_iter.c:185
 copy_page_to_iter+0x171/0x2b0 lib/iov_iter.c:362
 copy_folio_to_iter include/linux/uio.h:189 [inline]
 filemap_read+0x426/0x680 mm/filemap.c:2692
 blkdev_read_iter+0x20e/0x2c0 block/fops.c:765
 new_sync_read fs/read_write.c:488 [inline]
 vfs_read+0x5f6/0x720 fs/read_write.c:569
 ksys_read+0xeb/0x1b0 fs/read_write.c:712
 __do_sys_read fs/read_write.c:722 [inline]
 __se_sys_read fs/read_write.c:720 [inline]
 __x64_sys_read+0x42/0x50 fs/read_write.c:720
 x64_sys_call+0x27d3/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:1
 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3961 Comm: udevd Not tainted 6.11.0-syzkaller-08829-gaf9c191ac2a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/22 23:02 upstream af9c191ac2a0 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _copy_to_iter / fat_set_state
* Struck through repros no longer work on HEAD.