syzbot


KCSAN: data-race in shmem_getattr / shmem_recalc_inode

Status: moderation: reported on 2024/07/04 23:41
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+dfb578404df369f6599b@syzkaller.appspotmail.com
First crash: 404d, last: 14h34m

Sample crash report:
==================================================================
BUG: KCSAN: data-race in shmem_getattr / shmem_recalc_inode

read-write to 0xffff888119a07178 of 8 bytes by task 4311 on cpu 0:
 shmem_recalc_inode+0x3b/0x200 mm/shmem.c:445
 shmem_alloc_and_add_folio mm/shmem.c:2005 [inline]
 shmem_get_folio_gfp+0x7a3/0xd60 mm/shmem.c:2597
 shmem_get_folio mm/shmem.c:2703 [inline]
 shmem_write_begin+0xa8/0x190 mm/shmem.c:3353
 generic_perform_write+0x184/0x490 mm/filemap.c:4175
 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3528
 __kernel_write_iter+0x2d6/0x540 fs/read_write.c:619
 dump_emit_page fs/coredump.c:1296 [inline]
 dump_user_range+0x61e/0x8f0 fs/coredump.c:1370
 elf_core_dump+0x1e00/0x1f90 fs/binfmt_elf.c:2085
 coredump_write+0xb0d/0xe30 fs/coredump.c:1049
 vfs_coredump+0x142f/0x20c0 fs/coredump.c:1168
 get_signal+0xd85/0xf70 kernel/signal.c:3019
 arch_do_signal_or_restart+0x96/0x480 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 irqentry_exit_to_user_mode+0x5e/0xa0 kernel/entry/common.c:73
 irqentry_exit+0x12/0x50 kernel/entry/common.c:177
 exc_general_protection+0x15b/0x1f0 arch/x86/kernel/traps.c:792
 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617

read to 0xffff888119a07178 of 8 bytes by task 3306 on cpu 1:
 shmem_getattr+0x41/0x200 mm/shmem.c:1282
 vfs_getattr_nosec+0x143/0x1e0 fs/stat.c:213
 vfs_getattr fs/stat.c:262 [inline]
 vfs_statx_path fs/stat.c:299 [inline]
 vfs_statx+0x113/0x390 fs/stat.c:356
 vfs_fstatat+0x115/0x170 fs/stat.c:375
 __do_sys_newfstatat fs/stat.c:542 [inline]
 __se_sys_newfstatat+0x55/0x260 fs/stat.c:536
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:536
 x64_sys_call+0x135a/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:263
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000000004dd -> 0x00000000000004de

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3306 Comm: syz-executor Not tainted 6.17.0-rc1-syzkaller-00014-g0e39a731820a #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
==================================================================

Crashes (115):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/13 06:13 upstream 0e39a731820a 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/08/12 13:38 upstream 53e760d89498 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/08/05 06:28 upstream d632ab86aff2 f5bcc8dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/08/02 21:09 upstream a6923c06a3b2 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/08/02 12:33 upstream 0905809b38bd 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/07/28 04:25 upstream b711733e89a3 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/07/21 14:55 upstream 89be9a83ccf1 56d87229 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/07/19 15:45 upstream 4871b7cb27f4 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/07/17 20:16 upstream e2291551827f 0d1223f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/07/14 01:50 upstream 5d5d62298b8b 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/07/11 12:32 upstream bc9ff192a6c9 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/07/06 14:00 upstream 1f988d0788f5 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/07/05 20:13 upstream a79a588fc176 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/07/04 00:06 upstream 17bbde2e1716 76ad128c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/30 22:12 upstream d0b3b7b22dfa 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/30 06:43 upstream d0b3b7b22dfa fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/28 00:32 upstream 67a993863163 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/25 06:35 upstream 7595b66ae9de 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/14 20:09 upstream 4774cfe3543a 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/10 19:42 upstream f09079bd04a9 5d7e17ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/06 14:00 upstream e271ed52b344 9fa58bba .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/05 12:15 upstream 1af80d00e1e0 6b6b5f21 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/03 15:45 upstream 546b1c9e93c2 a30356b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/06/02 14:17 upstream cd2e103d57e5 b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/05/30 06:44 upstream e0797d3b91de 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/05/17 15:50 upstream 172a9d94339c f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/05/17 04:40 upstream 3c21441eeffc f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/05/10 10:27 upstream 0e1329d4045c 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/04/30 04:31 upstream ca91b9500108 85a5a23f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/04/28 22:56 upstream f15d97df5afa aeb6ec69 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/04/23 12:30 upstream bc3372351d0c 53a8b9bd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/04/20 18:57 upstream 6fea5fabd332 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/04/19 19:09 upstream 8560697b23dc 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/04/11 19:01 upstream 900241a5cc15 94486846 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/04/04 14:15 upstream e48e99b6edf4 1c4febdb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/04/01 03:25 upstream 1e7857b28020 36d76a97 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/30 03:14 upstream 7d06015d936c d3999433 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/29 13:59 upstream 7d06015d936c cf25e2c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/26 23:17 upstream 2df0c02dab82 20510e88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/26 15:59 upstream 2df0c02dab82 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/23 13:54 upstream 183601b78a9b 4e8d3850 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/20 07:21 upstream a7f2e10ecd8f 9209bc22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/16 19:43 upstream cb82ca153949 e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/13 01:42 upstream 0fed89a961ea 1a5d9317 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/09 03:18 upstream b7c90e3e717a 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2025/03/07 21:03 upstream 00a7d39898c8 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
2024/07/04 23:41 upstream 661e504db04c 3f2748a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in shmem_getattr / shmem_recalc_inode
* Struck through repros no longer work on HEAD.