syzbot


KCSAN: data-race in shmem_get_folio_gfp / shmem_setattr (4)

Status: auto-obsoleted due to no activity on 2024/03/08 00:53
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+180a8f05279e5c1f5129@syzkaller.appspotmail.com
First crash: 89d, last: 77d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in shmem_get_folio_gfp / shmem_setattr (3) mm 1 255d 255d 0/26 auto-obsoleted due to no activity on 2023/09/11 12:50
upstream KCSAN: data-race in shmem_get_folio_gfp / shmem_setattr (2) mm 1 300d 300d 0/26 auto-obsoleted due to no activity on 2023/07/29 00:25
upstream KCSAN: data-race in shmem_get_folio_gfp / shmem_setattr mm 1 381d 381d 0/26 auto-obsoleted due to no activity on 2023/05/08 09:10

Sample crash report:
==================================================================
BUG: KCSAN: data-race in shmem_get_folio_gfp / shmem_setattr

write to 0xffff8881b430de30 of 8 bytes by task 30753 on cpu 1:
 i_size_write include/linux/fs.h:932 [inline]
 shmem_setattr+0x6fb/0x830 mm/shmem.c:1186
 notify_change+0x866/0x8e0 fs/attr.c:499
 do_truncate+0x116/0x150 fs/open.c:66
 do_sys_ftruncate+0x2ba/0x3b0 fs/open.c:194
 __do_sys_ftruncate fs/open.c:205 [inline]
 __se_sys_ftruncate fs/open.c:203 [inline]
 __x64_sys_ftruncate+0x33/0x40 fs/open.c:203
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff8881b430de30 of 8 bytes by task 30750 on cpu 0:
 i_size_read include/linux/fs.h:910 [inline]
 shmem_get_folio_gfp+0x13f/0xb40 mm/shmem.c:1973
 shmem_get_folio mm/shmem.c:2134 [inline]
 shmem_file_splice_read+0x198/0x600 mm/shmem.c:2964
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x268/0x660 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3b9/0x960 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000000080079a0 -> 0x0000000000007f2d

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 30750 Comm: syz-executor.1 Not tainted 6.8.0-rc2-syzkaller-00084-g5c24e4e9e708 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/02 00:52 upstream 5c24e4e9e708 d61103fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_get_folio_gfp / shmem_setattr
2024/01/20 18:41 upstream 125514880ddd 9bd8dcda .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_get_folio_gfp / shmem_setattr
* Struck through repros no longer work on HEAD.