VFS: Found a Xenix FS (block size = 1024) on device loop4 attempt to access beyond end of device loop4: rw=0, want=6491538, limit=128 Buffer I/O error on dev loop4, logical block 3245768, async page read ================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0x10b4/0x1240 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff8880551f21ce by task syz.4.1440/9237 CPU: 1 PID: 9237 Comm: syz.4.1440 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 sysv_new_inode+0x10b4/0x1240 fs/sysv/ialloc.c:153 sysv_mknod+0x4a/0xd0 fs/sysv/namei.c:53 lookup_open fs/namei.c:3462 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x11e1/0x2f30 fs/namei.c:3739 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f83b0cd2ec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f83aef3a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f83b0f29fa0 RCX: 00007f83b0cd2ec9 RDX: 000000000000275a RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f83b0d55f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f83b0f2a038 R14: 00007f83b0f29fa0 R15: 00007ffeb0a4f7c8 The buggy address belongs to the page: page:ffffea0001547c80 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x100 pfn:0x551f2 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001506b08 ffffea0001641408 0000000000000000 raw: 0000000000000100 0000000000000001 00000000ffffff7f 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 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 9090, ts 378056636433, free_ts 379212351859 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146 wp_page_copy+0x206/0x1fd0 mm/memory.c:3051 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1eca/0x43c0 mm/memory.c:4883 faultin_page mm/gup.c:976 [inline] __get_user_pages+0x93e/0x11c0 mm/gup.c:1197 __get_user_pages_locked mm/gup.c:1382 [inline] get_user_pages_unlocked+0x248/0x6f0 mm/gup.c:2222 __gup_longterm_unlocked mm/gup.c:2823 [inline] internal_get_user_pages_fast+0x1c9d/0x2080 mm/gup.c:2911 iov_iter_get_pages+0x225/0x5b0 lib/iov_iter.c:1544 af_alg_make_sg+0xa7/0x4c0 crypto/af_alg.c:410 af_alg_get_rsgl+0x34f/0x690 crypto/af_alg.c:1192 _skcipher_recvmsg crypto/algif_skcipher.c:77 [inline] skcipher_recvmsg+0x320/0xd20 crypto/algif_skcipher.c:157 ____sys_recvmsg+0x291/0x580 net/socket.c:-1 ___sys_recvmsg+0x1af/0x4f0 net/socket.c:2697 __sys_recvmsg net/socket.c:2727 [inline] __do_sys_recvmsg net/socket.c:2737 [inline] __se_sys_recvmsg net/socket.c:2734 [inline] __x64_sys_recvmsg+0x1dd/0x2a0 net/socket.c:2734 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page_list+0x122/0x7e0 mm/page_alloc.c:3433 release_pages+0x184b/0x1bb0 mm/swap.c:963 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu+0xc5/0x170 mm/mmu_gather.c:247 zap_pte_range mm/memory.c:1456 [inline] zap_pmd_range mm/memory.c:1505 [inline] zap_pud_range mm/memory.c:1534 [inline] zap_p4d_range mm/memory.c:1555 [inline] unmap_page_range+0x2096/0x2520 mm/memory.c:1576 unmap_vmas+0x11b/0x230 mm/memory.c:1653 exit_mmap+0x38f/0x5f0 mm/mmap.c:3216 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x567/0x6c0 kernel/exit.c:550 do_exit+0x5a1/0x20a0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 Memory state around the buggy address: ffff8880551f2080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880551f2100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8880551f2180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880551f2200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880551f2280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================