KASAN: invalid-free in crypt_dec_pending

Status: premoderation: reported on 2026/10/23 03:58
Reported-by: syzbot+5aca6db922391714a3d4@syzkaller.appspotmail.com
First crash: 11d, last: 11d

Sample crash report:
==================================================================
BUG: KASAN: double-free in slab_free mm/slub.c:3712 [inline]
BUG: KASAN: double-free in __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728
Free of addr ffff888115e59400 by task kworker/1:1/39

CPU: 1 PID: 39 Comm: kworker/1:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: kcryptd_io/252:4 kcryptd_io_read_work
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x71/0x200 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:420
 kasan_report_invalid_free+0xd5/0xf0 mm/kasan/report.c:489
 ____kasan_slab_free+0x14f/0x180 mm/kasan/common.c:-1
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250
 kasan_slab_free include/linux/kasan.h:178 [inline]
 slab_free_hook mm/slub.c:1750 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776
 slab_free mm/slub.c:3712 [inline]
 __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728
 kfree+0x6f/0xf0 mm/slab_common.c:990
 crypt_dec_pending+0x231/0x600 drivers/md/dm-crypt.c:1778
 kcryptd_io_read_work+0x84/0xa0 drivers/md/dm-crypt.c:1889
 process_one_work+0x717/0xc30 kernel/workqueue.c:2302
 worker_thread+0xa4d/0x11d0 kernel/workqueue.c:2449
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Allocated by task 691:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:380 [inline]
 __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389
 kasan_kmalloc include/linux/kasan.h:212 [inline]
 __do_kmalloc_node mm/slab_common.c:938 [inline]
 __kmalloc+0xb4/0x1e0 mm/slab_common.c:951
 kmalloc include/linux/slab.h:568 [inline]
 crypt_map+0x417/0xbc0 drivers/md/dm-crypt.c:3445
 __map_bio+0x159/0xb50 drivers/md/dm.c:-1
 __split_and_process_bio drivers/md/dm.c:1704 [inline]
 dm_split_and_process_bio drivers/md/dm.c:1760 [inline]
 dm_submit_bio+0xf0c/0x1ce0 drivers/md/dm.c:1816
 __submit_bio+0x222/0x380 block/blk-core.c:602
 __submit_bio_noacct block/blk-core.c:645 [inline]
 submit_bio_noacct_nocheck+0x3d0/0x950 block/blk-core.c:708
 submit_bio_noacct+0xded/0x1780 block/blk-core.c:801
 submit_bio+0x1ae/0x2a0 block/blk-core.c:846
 submit_bh_wbc+0x491/0x4f0 fs/buffer.c:2750
 submit_bh fs/buffer.c:2755 [inline]
 __bh_read fs/buffer.c:3024 [inline]
 bh_read_nowait include/linux/buffer_head.h:427 [inline]
 __block_write_begin_int+0x108b/0x13f0 fs/buffer.c:2064
 __block_write_begin fs/buffer.c:2084 [inline]
 block_write_begin+0x94/0x110 fs/buffer.c:2145
 blkdev_write_begin+0x34/0x40 block/fops.c:407
 generic_perform_write+0x32d/0x740 mm/filemap.c:3927
 blkdev_write_iter+0x49b/0x6b0 block/fops.c:601
 call_write_iter include/linux/fs.h:2282 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x5ef/0xd00 fs/read_write.c:584
 ksys_pwrite64 fs/read_write.c:699 [inline]
 __do_sys_pwrite64 fs/read_write.c:709 [inline]
 __se_sys_pwrite64 fs/read_write.c:706 [inline]
 __x64_sys_pwrite64+0x194/0x220 fs/read_write.c:706
 x64_sys_call+0x36/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:19
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 691:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250
 kasan_slab_free include/linux/kasan.h:178 [inline]
 slab_free_hook mm/slub.c:1750 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776
 slab_free mm/slub.c:3712 [inline]
 __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728
 kfree+0x6f/0xf0 mm/slab_common.c:990
 crypt_dec_pending+0x231/0x600 drivers/md/dm-crypt.c:1778
 kcryptd_io_read+0x4d9/0x5f0 drivers/md/dm-crypt.c:1873
 crypt_map+0x50b/0xbc0 drivers/md/dm-crypt.c:3460
 __map_bio+0x159/0xb50 drivers/md/dm.c:-1
 __split_and_process_bio drivers/md/dm.c:1704 [inline]
 dm_split_and_process_bio drivers/md/dm.c:1760 [inline]
 dm_submit_bio+0xf0c/0x1ce0 drivers/md/dm.c:1816
 __submit_bio+0x222/0x380 block/blk-core.c:602
 __submit_bio_noacct block/blk-core.c:645 [inline]
 submit_bio_noacct_nocheck+0x3d0/0x950 block/blk-core.c:708
 submit_bio_noacct+0xded/0x1780 block/blk-core.c:801
 submit_bio+0x1ae/0x2a0 block/blk-core.c:846
 submit_bh_wbc+0x491/0x4f0 fs/buffer.c:2750
 submit_bh fs/buffer.c:2755 [inline]
 __bh_read fs/buffer.c:3024 [inline]
 bh_read_nowait include/linux/buffer_head.h:427 [inline]
 __block_write_begin_int+0x108b/0x13f0 fs/buffer.c:2064
 __block_write_begin fs/buffer.c:2084 [inline]
 block_write_begin+0x94/0x110 fs/buffer.c:2145
 blkdev_write_begin+0x34/0x40 block/fops.c:407
 generic_perform_write+0x32d/0x740 mm/filemap.c:3927
 blkdev_write_iter+0x49b/0x6b0 block/fops.c:601
 call_write_iter include/linux/fs.h:2282 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x5ef/0xd00 fs/read_write.c:584
 ksys_pwrite64 fs/read_write.c:699 [inline]
 __do_sys_pwrite64 fs/read_write.c:709 [inline]
 __se_sys_pwrite64 fs/read_write.c:706 [inline]
 __x64_sys_pwrite64+0x194/0x220 fs/read_write.c:706
 x64_sys_call+0x36/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:19
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888115e59400
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 0 bytes inside of
 64-byte region [ffff888115e59400, ffff888115e59440)

The buggy address belongs to the physical page:
page:ffffea0004579640 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115e59
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000122 ffff888100042780
raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112c00(GFP_NOIO|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 691, tgid 690 (syz.4.159), ts 37207035011, free_ts 33964960656
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2673
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2680
 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4587
 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5931
 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
 allocate_slab mm/slub.c:1967 [inline]
 new_slab+0x98/0x3e0 mm/slub.c:2020
 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177
 __slab_alloc+0x5e/0xa0 mm/slub.c:3263
 slab_alloc_node mm/slub.c:3348 [inline]
 __kmem_cache_alloc_node+0x204/0x2d0 mm/slub.c:3423
 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028
 kmalloc include/linux/slab.h:563 [inline]
 kmalloc_array include/linux/slab.h:614 [inline]
 realloc_argv drivers/md/dm-table.c:488 [inline]
 dm_split_args+0x89/0x570 drivers/md/dm-table.c:514
 dm_table_add_target+0x589/0xcc0 drivers/md/dm-table.c:711
 populate_table drivers/md/dm-ioctl.c:1430 [inline]
 table_load+0x2ce/0x750 drivers/md/dm-ioctl.c:1472
 ctl_ioctl drivers/md/dm-ioctl.c:2037 [inline]
 dm_ctl_ioctl+0x95f/0xd00 drivers/md/dm-ioctl.c:2059
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1581 [inline]
 free_pcp_prepare mm/page_alloc.c:1655 [inline]
 free_unref_page_prepare+0x81b/0x820 mm/page_alloc.c:3622
 free_unref_page+0x93/0x530 mm/page_alloc.c:3720
 free_the_page mm/page_alloc.c:863 [inline]
 __free_pages+0x67/0x100 mm/page_alloc.c:6021
 __free_slab+0xc7/0x1a0 mm/slub.c:2044
 free_slab mm/slub.c:2059 [inline]
 discard_slab+0x29/0x40 mm/slub.c:2065
 __slab_free+0x201/0x280 mm/slub.c:3625
 do_slab_free mm/slub.c:3666 [inline]
 ___cache_free+0xbf/0xd0 mm/slub.c:3722
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:311
 kasan_slab_alloc include/linux/kasan.h:202 [inline]
 slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768
 slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc mm/slub.c:3392 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3399 [inline]
 kmem_cache_alloc+0x166/0x320 mm/slub.c:3408
 getname_flags+0xba/0x510 fs/namei.c:139
 vfs_fstatat fs/stat.c:266 [inline]
 __do_sys_newfstatat fs/stat.c:437 [inline]
 __se_sys_newfstatat+0x127/0x440 fs/stat.c:431
 __x64_sys_newfstatat+0x9b/0xb0 fs/stat.c:431
 x64_sys_call+0x77c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:263

Memory state around the buggy address:
 ffff888115e59300: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888115e59380: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff888115e59400: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff888115e59480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888115e59500: 00 00 00 00 00 00 00 03 fc fc fc fc fc fc fc fc
==================================================================
usb 1-1: USB disconnect, device number 3

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/23 03:58 android14-6.1 3ad9f1eca4fa b55fad29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: invalid-free in crypt_dec_pending
2026/10/23 03:58 android14-6.1 3ad9f1eca4fa b55fad29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: invalid-free in crypt_dec_pending
* Struck through repros no longer work on HEAD.