Zero length message leads to an empty skb loop0: detected capacity change from 0 to 128 ======================================================= WARNING: The mand mount option has been deprecated and and is ignored by this kernel. Remove the mand option from the mount to silence this warning. ======================================================= hpfs: filesystem error: invalid number of hotfixes: 2066844986, used: 2066844985; already mounted read-only hpfs: filesystem error: improperly stopped hpfs: filesystem error: warning: spare dnodes used, try chkdsk hpfs: You really don't want any checks? You are crazy... hpfs: hpfs_map_sector(): read error hpfs: code page support is disabled ================================================================== BUG: KASAN: use-after-free in strcmp+0x6b/0xc0 lib/string.c:283 Read of size 1 at addr ffff8880119758a6 by task syz.0.0/5314 CPU: 0 UID: 0 PID: 5314 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 strcmp+0x6b/0xc0 lib/string.c:283 hpfs_get_ea+0x134/0xee0 fs/hpfs/ea.c:139 hpfs_read_inode+0x1a6/0x1050 fs/hpfs/inode.c:63 hpfs_fill_super+0x123d/0x1fa0 fs/hpfs/super.c:651 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fea1c19d20a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fea1d117e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fea1d117ee0 RCX: 00007fea1c19d20a RDX: 000020000000a000 RSI: 0000200000009ec0 RDI: 00007fea1d117ea0 RBP: 000020000000a000 R08: 00007fea1d117ee0 R09: 0000000003200041 R10: 0000000003200041 R11: 0000000000000246 R12: 0000200000009ec0 R13: 00007fea1d117ea0 R14: 0000000000009e15 R15: 0000200000000140 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x7f732c14c pfn:0x11975 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea00008fa288 ffffea0000465788 0000000000000000 raw: 00000007f732c14c 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|__GFP_COMP), pid 5324, tgid 5324 (udevd), ts 91455151846, free_ts 91474968315 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1883 prep_new_page mm/page_alloc.c:1891 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3956 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5244 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2485 folio_alloc_mpol_noprof mm/mempolicy.c:2504 [inline] vma_alloc_folio_noprof+0xea/0x210 mm/mempolicy.c:2539 folio_prealloc mm/memory.c:-1 [inline] alloc_anon_folio mm/memory.c:5200 [inline] do_anonymous_page mm/memory.c:5257 [inline] do_pte_missing+0x1656/0x3750 mm/memory.c:4467 handle_pte_fault mm/memory.c:6308 [inline] __handle_mm_fault mm/memory.c:6446 [inline] handle_mm_fault+0x1bec/0x3310 mm/memory.c:6615 do_user_addr_fault+0x75b/0x1340 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 page last free pid 5324 tgid 5324 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1432 [inline] free_unref_folios+0xdd7/0x1520 mm/page_alloc.c:3034 folios_put_refs+0x789/0x8d0 mm/swap.c:1002 folios_put include/linux/mm.h:1675 [inline] folio_batch_move_lru+0x39d/0x430 mm/swap.c:179 lru_add_drain_cpu+0xb8/0x7b0 mm/swap.c:648 lru_add_drain+0x121/0x3e0 mm/swap.c:737 __folio_batch_release+0x48/0x90 mm/swap.c:1059 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x240/0x9e0 mm/shmem.c:1407 evict+0x61e/0xb10 fs/inode.c:846 __dentry_kill+0x1a2/0x5e0 fs/dcache.c:670 finish_dput+0xc9/0x480 fs/dcache.c:879 end_renaming fs/namei.c:4096 [inline] filename_renameat2+0x61e/0x9c0 fs/namei.c:6146 __do_sys_rename fs/namei.c:6188 [inline] __se_sys_rename+0x55/0x2c0 fs/namei.c:6184 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888011975780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888011975800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888011975880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888011975900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888011975980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================