syzbot


KASAN: use-after-free Read in __ocfs2_find_path

Status: upstream: reported C repro on 2024/10/05 20:46
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+e41668d5154370928317@syzkaller.appspotmail.com
First crash: 60d, last: 22d
Bug presence (1)
Date Name Commit Repro Result
2024/11/02 upstream (ToT) 11066801dd4b C [report] KASAN: use-after-free Read in __ocfs2_find_path
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in __ocfs2_find_path ocfs2 C inconclusive 58 2d04h 56d 0/28 upstream: reported C repro on 2024/10/09 20:34
linux-6.1 KASAN: use-after-free Read in __ocfs2_find_path origin:upstream C 5 22d 59d 0/3 upstream: reported C repro on 2024/10/07 07:25
Last patch testing requests (3)
Created Duration User Patch Repo Result
2024/10/20 18:50 17m retest repro linux-5.15.y report log
2024/10/20 18:50 18m retest repro linux-5.15.y report log
2024/10/20 18:50 17m retest repro linux-5.15.y report log

Sample crash report:
loop0: detected capacity change from 0 to 32768
==================================================================
BUG: KASAN: use-after-free in __ocfs2_find_path+0x1ff/0x7e0 fs/ocfs2/alloc.c:1817
Read of size 4 at addr ffff888065aa7000 by task syz-executor423/3570

CPU: 0 PID: 3570 Comm: syz-executor423 Not tainted 5.15.167-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 __ocfs2_find_path+0x1ff/0x7e0 fs/ocfs2/alloc.c:1817
 ocfs2_find_leaf+0xcb/0x220 fs/ocfs2/alloc.c:1931
 ocfs2_get_clusters_nocache+0x1a9/0xbe0 fs/ocfs2/extent_map.c:418
 ocfs2_get_clusters+0x5b5/0xbc0 fs/ocfs2/extent_map.c:621
 ocfs2_extent_map_get_blocks+0x248/0x7d0 fs/ocfs2/extent_map.c:668
 ocfs2_read_virt_blocks+0x2ea/0xa10 fs/ocfs2/extent_map.c:977
 ocfs2_read_dir_block fs/ocfs2/dir.c:508 [inline]
 ocfs2_find_entry_el fs/ocfs2/dir.c:715 [inline]
 ocfs2_find_entry+0x437/0x26d0 fs/ocfs2/dir.c:1080
 ocfs2_find_files_on_disk+0xea/0x310 fs/ocfs2/dir.c:1982
 ocfs2_lookup_ino_from_name+0xad/0x1e0 fs/ocfs2/dir.c:2004
 _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
 ocfs2_get_system_file_inode+0x314/0x7b0 fs/ocfs2/sysfile.c:112
 ocfs2_init_global_system_inodes+0x328/0x720 fs/ocfs2/super.c:458
 ocfs2_initialize_super fs/ocfs2/super.c:2276 [inline]
 ocfs2_fill_super+0x479e/0x58a0 fs/ocfs2/super.c:995
 mount_bdev+0x2c9/0x3f0 fs/super.c:1398
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1528
 do_new_mount+0x2ba/0xb40 fs/namespace.c:3005
 do_mount fs/namespace.c:3348 [inline]
 __do_sys_mount fs/namespace.c:3556 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3533
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1f9135743a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 1e 09 00 00 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1f91309088 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1f913090a0 RCX: 00007f1f9135743a
RDX: 0000000020004440 RSI: 0000000020000780 RDI: 00007f1f913090a0
RBP: 0000000000000004 R08: 00007f1f913090e0 R09: 0000000000004444
R10: 0000000001000000 R11: 0000000000000282 R12: 00007f1f913090e0
R13: 0000000001000000 R14: 0000000000000003 R15: 0000000001000000
 </TASK>

The buggy address belongs to the page:
page:ffffea000196a9c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x65aa7
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea000196aa08 ffff8880b9040960 0000000000000000
raw: 0000000000000001 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 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 3570, ts 46687290697, free_ts 46789887949
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423
 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146
 do_anonymous_page mm/memory.c:3808 [inline]
 handle_pte_fault mm/memory.c:4618 [inline]
 __handle_mm_fault mm/memory.c:4755 [inline]
 handle_mm_fault+0x2f49/0x5960 mm/memory.c:4853
 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline]
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568
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+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
 release_pages+0x1bb9/0x1f40 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 mm/mmu_gather.c:247 [inline]
 tlb_finish_mmu+0x177/0x320 mm/mmu_gather.c:338
 unmap_region+0x304/0x350 mm/mmap.c:2668
 __do_munmap+0x12db/0x1740 mm/mmap.c:2899
 __vm_munmap+0x134/0x230 mm/mmap.c:2922
 __do_sys_munmap mm/mmap.c:2948 [inline]
 __se_sys_munmap mm/mmap.c:2944 [inline]
 __x64_sys_munmap+0x67/0x70 mm/mmap.c:2944
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff888065aa6f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888065aa6f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888065aa7000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888065aa7080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888065aa7100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/05 21:04 linux-5.15.y 3a5928702e71 d7906eff .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ocfs2_find_path
2024/10/05 21:23 linux-5.15.y 3a5928702e71 d7906eff .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ocfs2_find_path
2024/10/05 21:05 linux-5.15.y 3a5928702e71 d7906eff .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ocfs2_find_path
2024/11/13 04:56 linux-5.15.y 3c17fc483905 62026c85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ocfs2_find_path
2024/11/13 04:55 linux-5.15.y 3c17fc483905 62026c85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ocfs2_find_path
2024/10/05 20:50 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ocfs2_find_path
2024/10/05 20:48 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ocfs2_find_path
2024/11/12 18:00 linux-5.15.y 3c17fc483905 75bb1b32 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ocfs2_find_path
2024/11/12 17:58 linux-5.15.y 3c17fc483905 75bb1b32 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ocfs2_find_path
2024/10/05 20:48 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ocfs2_find_path
2024/10/05 20:45 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ocfs2_find_path
* Struck through repros no longer work on HEAD.