================================================================== BUG: KASAN: slab-out-of-bounds in squashfs_get_id+0x1bc/0x1f0 fs/squashfs/id.c:51 Read of size 8 at addr ffff8880a0303860 by task syz-executor.4/27780 CPU: 0 PID: 27780 Comm: syz-executor.4 Not tainted 4.19.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x22c/0x33e lib/dump_stack.c:118 print_address_description.cold+0x56/0x25c mm/kasan/report.c:256 kasan_report_error.cold+0x66/0xb9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 squashfs_get_id+0x1bc/0x1f0 fs/squashfs/id.c:51 squashfs_new_inode fs/squashfs/inode.c:64 [inline] squashfs_read_inode+0x197/0x1940 fs/squashfs/inode.c:133 squashfs_fill_super+0x1277/0x190a fs/squashfs/super.c:318 mount_bdev+0x2fc/0x3b0 fs/super.c:1158 mount_fs+0xa3/0x318 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:2469 [inline] do_mount+0x51c/0x2f10 fs/namespace.c:2799 ksys_mount+0xcf/0x130 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3026 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x460bca Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 dd 87 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 ba 87 fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007f5c215eaa88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f5c215eab20 RCX: 0000000000460bca RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f5c215eaae0 RBP: 00007f5c215eaae0 R08: 00007f5c215eab20 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000 R13: 0000000020000100 R14: 00000000200003c0 R15: 0000000020000040 Allocated by task 3724: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc_track_caller+0x155/0x4e0 mm/slab.c:3742 kmemdup+0x23/0x50 mm/util.c:118 kmemdup include/linux/string.h:446 [inline] selinux_cred_prepare+0x44/0xa0 security/selinux/hooks.c:3982 security_prepare_creds+0x50/0xb0 security/security.c:1014 prepare_creds+0x32d/0x510 kernel/cred.c:282 do_faccessat+0x94/0x7f0 fs/open.c:359 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 3724: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x250 mm/slab.c:3822 security_cred_free+0x6d/0xb0 security/security.c:1009 put_cred_rcu+0x122/0x4a0 kernel/cred.c:117 __put_cred+0x1de/0x280 kernel/cred.c:151 put_cred include/linux/cred.h:276 [inline] do_faccessat+0x691/0x7f0 fs/open.c:438 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a0303840 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes to the right of 32-byte region [ffff8880a0303840, ffff8880a0303860) The buggy address belongs to the page: page:ffffea000280c0c0 count:1 mapcount:0 mapping:ffff88812c3f61c0 index:0xffff8880a0303fc1 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea00013e7e08 ffffea00027ab588 ffff88812c3f61c0 raw: ffff8880a0303fc1 ffff8880a0303000 000000010000003e 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a0303700: 00 00 fc fc fc fc fc fc 00 fc fc fc fc fc fc fc ffff8880a0303780: fb fb fb fb fc fc fc fc 05 fc fc fc fc fc fc fc >ffff8880a0303800: 00 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff8880a0303880: 00 00 fc fc fc fc fc fc fb fb fb fb fc fc fc fc ffff8880a0303900: 05 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ==================================================================