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KCSAN: data-race in loop_configure / shmem_write_begin (6)

Status: auto-obsoleted due to no activity on 2024/03/02 02:49
Subsystems: block
[Documentation on labels]
Reported-by: syzbot+eac05ae4e92a7e87b398@syzkaller.appspotmail.com
First crash: 83d, last: 83d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in loop_configure / shmem_write_begin (4) block 5 260d 345d 0/26 auto-obsoleted due to no activity on 2023/09/06 15:54
upstream KCSAN: data-race in loop_configure / shmem_write_begin (2) block 1 548d 548d 0/26 auto-obsoleted due to no activity on 2022/11/22 19:17
upstream KCSAN: data-race in loop_configure / shmem_write_begin (5) block 3 159d 131d 0/26 auto-obsoleted due to no activity on 2023/12/24 00:08
upstream KCSAN: data-race in loop_configure / shmem_write_begin (3) block 3 505d 513d 0/26 auto-obsoleted due to no activity on 2023/01/16 15:13
upstream KCSAN: data-race in loop_configure / shmem_write_begin block 1 1023d 1023d 0/26 auto-closed as invalid on 2021/09/03 06:19

Sample crash report:
==================================================================
BUG: KCSAN: data-race in loop_configure / shmem_write_begin

read-write to 0xffff88811af7c528 of 4 bytes by task 29422 on cpu 0:
 mapping_set_gfp_mask include/linux/pagemap.h:344 [inline]
 loop_configure+0x7c0/0xca0 drivers/block/loop.c:1073
 lo_ioctl+0x682/0x12e0
 blkdev_ioctl+0x375/0x460 block/ioctl.c:634
 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+0x59/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88811af7c528 of 4 bytes by task 29410 on cpu 1:
 mapping_gfp_mask include/linux/pagemap.h:328 [inline]
 shmem_get_folio mm/shmem.c:2135 [inline]
 shmem_write_begin+0x84/0x1b0 mm/shmem.c:2717
 generic_perform_write+0x1c9/0x410 mm/filemap.c:3930
 shmem_file_write_iter+0xc8/0xe0 mm/shmem.c:2893
 call_write_iter include/linux/fs.h:2085 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x760/0x8d0 fs/read_write.c:590
 ksys_write+0xeb/0x1a0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00100cca -> 0x00100c0a

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29410 Comm: syz-executor.1 Not tainted 6.8.0-rc1-syzkaller-00311-g3a5879d495b2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/01/27 02:48 upstream 3a5879d495b2 cc4a4020 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in loop_configure / shmem_write_begin
* Struck through repros no longer work on HEAD.