================================================================== BUG: KASAN: slab-out-of-bounds in find_first_zero_bit+0x84/0x90 lib/find_bit.c:105 Read of size 8 at addr ffff8880b5453e00 by task syz-executor132/7972 CPU: 0 PID: 7972 Comm: syz-executor132 Not tainted 4.14.295-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430 find_first_zero_bit+0x84/0x90 lib/find_bit.c:105 bfs_create+0xfb/0x620 fs/bfs/dir.c:92 lookup_open+0x77a/0x1750 fs/namei.c:3241 do_last fs/namei.c:3334 [inline] path_openat+0xe08/0x2970 fs/namei.c:3571 do_filp_open+0x179/0x3c0 fs/namei.c:3605 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fe978b9b0c9 RSP: 002b:00007ffd42be10e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe978b9b0c9 RDX: 00007fe978b593d3 RSI: 0000000000000000 RDI: 0000000020000940 RBP: 00007fe978b5a6a0 R08: 00005555566bd2c0 R09: 0000000000000000 R10: 00007ffd42be0fb0 R11: 0000000000000246 R12: 00007fe978b5a730 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7972: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15a/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:661 [inline] bfs_fill_super+0x3d5/0xd80 fs/bfs/inode.c:363 mount_bdev+0x2b3/0x360 fs/super.c:1134 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] do_mount+0xe65/0x2a30 fs/namespace.c:2905 SYSC_mount fs/namespace.c:3121 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3098 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 6217: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 aa_free_task_context+0xda/0x130 security/apparmor/context.c:54 apparmor_cred_free+0x34/0x70 security/apparmor/lsm.c:58 security_cred_free+0x71/0xb0 security/security.c:1003 put_cred_rcu+0xe3/0x300 kernel/cred.c:117 __put_cred+0x1a1/0x210 kernel/cred.c:151 put_cred include/linux/cred.h:274 [inline] SYSC_faccessat fs/open.c:444 [inline] SyS_faccessat+0x52a/0x680 fs/open.c:353 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff8880b5453e00 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8880b5453e00, ffff8880b5453e20) The buggy address belongs to the page: page:ffffea0002d514c0 count:1 mapcount:0 mapping:ffff8880b5453000 index:0xffff8880b5453fc1 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff8880b5453000 ffff8880b5453fc1 0000000100000031 raw: ffffea0002c468a0 ffffea0002c13520 ffff88813fe741c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880b5453d00: fb fb fb fb fc fc fc fc 00 01 fc fc fc fc fc fc ffff8880b5453d80: 00 01 fc fc fc fc fc fc fb fb fb fb fc fc fc fc >ffff8880b5453e00: 07 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff8880b5453e80: 00 00 fc fc fc fc fc fc fb fb fb fb fc fc fc fc ffff8880b5453f00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ==================================================================