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KCSAN: data-race in loop_configure / loop_queue_rq (3)

Status: auto-obsoleted due to no activity on 2023/05/10 10:38
Subsystems: block
[Documentation on labels]
First crash: 475d, last: 388d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in loop_configure / loop_queue_rq (4) block 1 276d 276d 0/26 auto-obsoleted due to no activity on 2023/08/30 01:13
upstream KCSAN: data-race in loop_configure / loop_queue_rq (2) block 1 538d 538d 0/26 auto-obsoleted due to no activity on 2022/12/10 20:51
upstream KCSAN: data-race in loop_configure / loop_queue_rq block 5 576d 622d 0/26 auto-obsoleted due to no activity on 2022/11/02 13:12

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

write to 0xffff888100eb7278 of 4 bytes by task 14528 on cpu 1:
 loop_configure+0xb0c/0xca0 drivers/block/loop.c:1105
 lo_ioctl+0x688/0x12f0
 blkdev_ioctl+0x3a0/0x490 block/ioctl.c:615
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:856
 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 0xffff888100eb7278 of 4 bytes by task 31787 on cpu 0:
 loop_queue_rq+0x4f/0x650 drivers/block/loop.c:1826
 __blk_mq_issue_directly block/blk-mq.c:2587 [inline]
 __blk_mq_try_issue_directly+0x2ba/0x420 block/blk-mq.c:2640
 blk_mq_request_issue_directly block/blk-mq.c:2674 [inline]
 blk_mq_plug_issue_direct+0x15d/0x520 block/blk-mq.c:2695
 blk_mq_flush_plug_list+0x2cf/0x660 block/blk-mq.c:2783
 __blk_flush_plug+0x223/0x280 block/blk-core.c:1153
 blk_finish_plug+0x47/0x60 block/blk-core.c:1177
 read_pages+0x4e5/0x560 mm/readahead.c:184
 page_cache_ra_unbounded+0x2a9/0x2e0 mm/readahead.c:270
 do_page_cache_ra mm/readahead.c:300 [inline]
 force_page_cache_ra mm/readahead.c:331 [inline]
 page_cache_sync_ra+0x251/0x2a0 mm/readahead.c:705
 page_cache_sync_readahead include/linux/pagemap.h:1214 [inline]
 filemap_get_pages+0x257/0xea0 mm/filemap.c:2598
 filemap_read+0x223/0x680 mm/filemap.c:2693
 blkdev_read_iter+0x2ca/0x370 block/fops.c:606
 call_read_iter include/linux/fs.h:1845 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x39a/0x560 fs/read_write.c:470
 ksys_read+0xeb/0x1a0 fs/read_write.c:613
 __do_sys_read fs/read_write.c:623 [inline]
 __se_sys_read fs/read_write.c:621 [inline]
 __x64_sys_read+0x42/0x50 fs/read_write.c:621
 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: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31787 Comm: udevd Not tainted 6.3.0-rc5-syzkaller-00022-g76f598ba7d8e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
==================================================================
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop0, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop3, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop1, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Buffer I/O error on dev loop5, logical block 0, async page read
Buffer I/O error on dev loop0, logical block 0, async page read
Buffer I/O error on dev loop1, logical block 0, async page read

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/04/05 10:29 upstream 76f598ba7d8e 831373d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in loop_configure / loop_queue_rq
2023/02/08 08:22 upstream 513c1a3d3f19 15c3d445 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in loop_configure / loop_queue_rq
2023/01/07 22:44 upstream 0a71553536d2 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in loop_configure / loop_queue_rq
* Struck through repros no longer work on HEAD.