Hello, syzbot found the following issue on: HEAD commit: fc4354c6e5c2 Merge tag 'mm-stable-2023-05-06-10-49' of git.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=144e2512280000 kernel config: https://syzkaller.appspot.com/x/.config?x=73a06f6ef2d5b492 dashboard link: https://syzkaller.appspot.com/bug?extid=34a0f26f0f61c4888ea4 compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/5f4adc5d40b0/disk-fc4354c6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/0e06af6b6985/vmlinux-fc4354c6.xz kernel image: https://storage.googleapis.com/syzbot-assets/7d99bbab1361/bzImage-fc4354c6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+34a0f26f0f61c4888ea4@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in ext4_search_dir+0xf2/0x1b0 fs/ext4/namei.c:1523 Read of size 1 at addr ffff88807ed202cc by task syz-executor.2/19699 CPU: 0 PID: 19699 Comm: syz-executor.2 Not tainted 6.3.0-syzkaller-13466-gfc4354c6e5c2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:351 [inline] print_report+0x163/0x540 mm/kasan/report.c:462 kasan_report+0x176/0x1b0 mm/kasan/report.c:572 ext4_search_dir+0xf2/0x1b0 fs/ext4/namei.c:1523 ext4_find_inline_entry+0x4ba/0x5e0 fs/ext4/inline.c:1708 __ext4_find_entry+0x2b4/0x1b30 fs/ext4/namei.c:1596 ext4_lookup_entry fs/ext4/namei.c:1751 [inline] ext4_lookup+0x17a/0x750 fs/ext4/namei.c:1819 lookup_one_qstr_excl+0x11b/0x250 fs/namei.c:1605 do_renameat2+0x6e1/0x1660 fs/namei.c:4952 __do_sys_rename fs/namei.c:5048 [inline] __se_sys_rename fs/namei.c:5046 [inline] __x64_sys_rename+0x86/0x90 fs/namei.c:5046 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9f7ce8c169 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 RSP: 002b:00007f9f7dc30168 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007f9f7cfabf80 RCX: 00007f9f7ce8c169 RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000020000440 RBP: 00007f9f7cee7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd9ebba38f R14: 00007f9f7dc30300 R15: 0000000000022000 </TASK> The buggy address belongs to the physical page: page:ffffea0001fb4800 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x7ed20 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffff7f(buddy) raw: 00fff00000000000 ffffea0001e19608 ffffea00012b0208 0000000000000000 raw: 0000000000000000 0000000000000003 00000000ffffff7f 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 15769, tgid 15769 (udevd), ts 3435881805689, free_ts 3440975634402 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1731 prep_new_page mm/page_alloc.c:1738 [inline] get_page_from_freelist+0x321c/0x33a0 mm/page_alloc.c:3502 __alloc_pages+0x255/0x670 mm/page_alloc.c:4768 alloc_slab_page+0x6a/0x160 mm/slub.c:1851 allocate_slab mm/slub.c:1998 [inline] new_slab+0x84/0x2f0 mm/slub.c:2051 ___slab_alloc+0xa85/0x10a0 mm/slub.c:3192 __slab_alloc mm/slub.c:3291 [inline] __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x1b9/0x2e0 mm/slub.c:3475 getname_flags+0xbc/0x4e0 fs/namei.c:140 do_sys_openat2+0xd6/0x500 fs/open.c:1350 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x247/0x290 fs/open.c:1383 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1302 [inline] free_unref_page_prepare+0x903/0xa30 mm/page_alloc.c:2564 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2659 discard_slab mm/slub.c:2097 [inline] __unfreeze_partials+0x1b1/0x1f0 mm/slub.c:2636 put_cpu_partial+0x116/0x180 mm/slub.c:2712 qlist_free_all+0x22/0x60 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook+0x68/0x3a0 mm/slab.h:711 slab_alloc_node mm/slub.c:3451 [inline] kmem_cache_alloc_node+0x157/0x350 mm/slub.c:3496 __alloc_skb+0x181/0x420 net/core/skbuff.c:644 alloc_skb include/linux/skbuff.h:1288 [inline] alloc_skb_with_frags+0xa8/0x750 net/core/skbuff.c:6378 sock_alloc_send_pskb+0x919/0xa50 net/core/sock.c:2729 unix_dgram_sendmsg+0x5b5/0x2050 net/unix/af_unix.c:1944 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] __sys_sendto+0x475/0x630 net/socket.c:2144 __do_sys_sendto net/socket.c:2156 [inline] __se_sys_sendto net/socket.c:2152 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2152 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff88807ed20180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807ed20200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88807ed20280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88807ed20300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807ed20380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to change bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
