================================================================== BUG: KASAN: slab-out-of-bounds in find_first_zero_bit+0xa8/0xb0 lib/find_bit.c:125 Read of size 8 at addr ffff8880b28d3e40 by task syz-executor.1/10514 CPU: 0 PID: 10514 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 find_first_zero_bit+0xa8/0xb0 lib/find_bit.c:125 bfs_create+0xfb/0x610 fs/bfs/dir.c:91 lookup_open+0x893/0x1a20 fs/namei.c:3235 do_last fs/namei.c:3327 [inline] path_openat+0x1094/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f66781fc0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 BTRFS: device fsid c9fe44da-de57-406a-8241-57ec7d4412cf devid 1 transid 8 /dev/loop0 RSP: 002b:00007f667676e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f667831bf80 RCX: 00007f66781fc0f9 RDX: 0000000000000000 RSI: 000000000014d27e RDI: 0000000020000180 RBP: 00007f6678257ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffedede50cf R14: 00007f667676e300 R15: 0000000000022000 Allocated by task 10514: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] kzalloc include/linux/slab.h:709 [inline] bfs_fill_super+0x447/0xec0 fs/bfs/inode.c:363 mount_bdev+0x2fc/0x3b0 fs/super.c:1158 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9536: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 load_elf_binary+0x41eb/0x5050 fs/binfmt_elf.c:1108 search_binary_handler.part.0+0xf9/0x4e0 fs/exec.c:1668 search_binary_handler fs/exec.c:1657 [inline] exec_binprm fs/exec.c:1710 [inline] __do_execve_file+0x1357/0x2360 fs/exec.c:1832 do_execveat_common fs/exec.c:1879 [inline] do_execve+0x35/0x50 fs/exec.c:1896 call_usermodehelper_exec_async+0x50e/0x6a0 kernel/umh.c:116 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff8880b28d3e40 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8880b28d3e40, ffff8880b28d3e60) The buggy address belongs to the page: page:ffffea0002ca34c0 count:1 mapcount:0 mapping:ffff88813bff01c0 index:0xffff8880b28d3fc1 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffffea0002ca4348 ffffea0002d39048 ffff88813bff01c0 raw: ffff8880b28d3fc1 ffff8880b28d3000 000000010000003f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880b28d3d00: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc ffff8880b28d3d80: 05 fc fc fc fc fc fc fc 00 03 fc fc fc fc fc fc >ffff8880b28d3e00: 00 fc fc fc fc fc fc fc 07 fc fc fc fc fc fc fc ^ ffff8880b28d3e80: 05 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ffff8880b28d3f00: 00 03 fc fc fc fc fc fc 00 03 fc fc fc fc fc fc ==================================================================