syzbot


KASAN: use-after-free Read in f2fs_iget

Status: upstream: reported C repro on 2024/05/05 12:48
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+0b1e85354f790743db08@syzkaller.appspotmail.com
First crash: 38d, last: 38d
Bug presence (1)
Date Name Commit Repro Result
2024/05/05 upstream (ToT) 7367539ad4b0 C [report] KASAN: slab-use-after-free Read in sanity_check_extent_cache
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 UBSAN: array-index-out-of-bounds in f2fs_iget origin:upstream C done 1 297d 297d 3/3 fixed on 2023/10/10 21:47
upstream UBSAN: array-index-out-of-bounds in f2fs_iget f2fs C done 6 284d 329d 23/28 fixed on 2023/10/12 12:48
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2024/06/12 20:08 1m bisect fix linux-5.15.y error job log (0)
2024/06/12 17:40 1m bisect fix linux-5.15.y error job log (0)
2024/06/05 19:37 10m bisect fix linux-5.15.y error job log (0)
marked invalid by web-security-scanner@google.com

Sample crash report:
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
==================================================================
BUG: KASAN: use-after-free in sanity_check_inode fs/f2fs/inode.c:272 [inline]
BUG: KASAN: use-after-free in do_read_inode fs/f2fs/inode.c:406 [inline]
BUG: KASAN: use-after-free in f2fs_iget+0x3f0c/0x53b8 fs/f2fs/inode.c:505
Read of size 4 at addr ffff0000deced028 by task syz-executor491/3997

CPU: 0 PID: 3997 Comm: syz-executor491 Not tainted 5.15.158-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x174/0x1e4 mm/kasan/report.c:451
 __asan_report_load4_noabort+0x44/0x50 mm/kasan/report_generic.c:308
 sanity_check_inode fs/f2fs/inode.c:272 [inline]
 do_read_inode fs/f2fs/inode.c:406 [inline]
 f2fs_iget+0x3f0c/0x53b8 fs/f2fs/inode.c:505
 f2fs_nfs_get_inode+0x80/0x118 fs/f2fs/super.c:3091
 generic_fh_to_dentry+0x9c/0x104 fs/libfs.c:1044
 f2fs_fh_to_dentry+0x44/0x58 fs/f2fs/super.c:3105
 exportfs_decode_fh_raw+0x114/0x4b4 fs/exportfs/expfs.c:436
 exportfs_decode_fh+0x50/0x80 fs/exportfs/expfs.c:576
 do_handle_to_path fs/fhandle.c:152 [inline]
 handle_to_path fs/fhandle.c:207 [inline]
 do_handle_open+0x5b8/0x9fc fs/fhandle.c:223
 __do_sys_open_by_handle_at fs/fhandle.c:265 [inline]
 __se_sys_open_by_handle_at fs/fhandle.c:256 [inline]
 __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:256
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Allocated by task 3972:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x8c/0xcc mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x74/0x3f4 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x1dc/0x45c mm/slub.c:3233
 f2fs_kmem_cache_alloc_nofail fs/f2fs/f2fs.h:2633 [inline]
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2643 [inline]
 __grab_extent_tree fs/f2fs/extent_cache.c:295 [inline]
 __f2fs_init_extent_tree fs/f2fs/extent_cache.c:381 [inline]
 f2fs_init_extent_tree+0x4c8/0xb70 fs/f2fs/extent_cache.c:404
 do_read_inode fs/f2fs/inode.c:383 [inline]
 f2fs_iget+0x1088/0x53b8 fs/f2fs/inode.c:505
 f2fs_nfs_get_inode+0x80/0x118 fs/f2fs/super.c:3091
 generic_fh_to_dentry+0x9c/0x104 fs/libfs.c:1044
 f2fs_fh_to_dentry+0x44/0x58 fs/f2fs/super.c:3105
 exportfs_decode_fh_raw+0x114/0x4b4 fs/exportfs/expfs.c:436
 exportfs_decode_fh+0x50/0x80 fs/exportfs/expfs.c:576
 do_handle_to_path fs/fhandle.c:152 [inline]
 handle_to_path fs/fhandle.c:207 [inline]
 do_handle_open+0x5b8/0x9fc fs/fhandle.c:223
 __do_sys_open_by_handle_at fs/fhandle.c:265 [inline]
 __se_sys_open_by_handle_at fs/fhandle.c:256 [inline]
 __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:256
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Freed by task 3972:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4c/0x84 mm/kasan/common.c:46
 kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360
 ____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0x128/0x1ec mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0xdc/0x3c4 mm/slub.c:3515
 f2fs_destroy_extent_tree+0x2e0/0x6e0 fs/f2fs/extent_cache.c:845
 f2fs_evict_inode+0x330/0x1564 fs/f2fs/inode.c:758
 evict+0x260/0x68c fs/inode.c:587
 iput_final fs/inode.c:1705 [inline]
 iput+0x744/0x824 fs/inode.c:1731
 iget_failed+0x154/0x1a4 fs/bad_inode.c:250
 f2fs_iget+0x588/0x53b8 fs/f2fs/inode.c:557
 f2fs_nfs_get_inode+0x80/0x118 fs/f2fs/super.c:3091
 generic_fh_to_dentry+0x9c/0x104 fs/libfs.c:1044
 f2fs_fh_to_dentry+0x44/0x58 fs/f2fs/super.c:3105
 exportfs_decode_fh_raw+0x114/0x4b4 fs/exportfs/expfs.c:436
 exportfs_decode_fh+0x50/0x80 fs/exportfs/expfs.c:576
 do_handle_to_path fs/fhandle.c:152 [inline]
 handle_to_path fs/fhandle.c:207 [inline]
 do_handle_open+0x5b8/0x9fc fs/fhandle.c:223
 __do_sys_open_by_handle_at fs/fhandle.c:265 [inline]
 __se_sys_open_by_handle_at fs/fhandle.c:256 [inline]
 __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:256
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the object at ffff0000deced000
 which belongs to the cache f2fs_extent_tree of size 136
The buggy address is located 40 bytes inside of
 136-byte region [ffff0000deced000, ffff0000deced088)
The buggy address belongs to the page:
page:00000000f4f3a067 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11eced
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c6604d80
raw: 0000000000000000 0000000080140014 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000dececf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000dececf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000deced000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff0000deced080: fb fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00
 ffff0000deced100: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
==================================================================
F2FS-fs (loop0): sanity_check_inode: inode (ino=8) extent info [5634, 0, 3] is incorrect, run fsck to fix
==================================================================
BUG: KASAN: double-free or invalid-free in slab_free mm/slub.c:3499 [inline]
BUG: KASAN: double-free or invalid-free in kmem_cache_free+0xdc/0x3c4 mm/slub.c:3515

CPU: 0 PID: 3997 Comm: syz-executor491 Tainted: G    B             5.15.158-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
 kasan_report_invalid_free+0x64/0x94 mm/kasan/report.c:373
 ____kasan_slab_free+0x134/0x164
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0x128/0x1ec mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0xdc/0x3c4 mm/slub.c:3515
 f2fs_destroy_extent_tree+0x2e0/0x6e0 fs/f2fs/extent_cache.c:845
 f2fs_evict_inode+0x330/0x1564 fs/f2fs/inode.c:758
 evict+0x260/0x68c fs/inode.c:587
 iput_final fs/inode.c:1705 [inline]
 iput+0x744/0x824 fs/inode.c:1731
 iget_failed+0x154/0x1a4 fs/bad_inode.c:250
 f2fs_iget+0x588/0x53b8 fs/f2fs/inode.c:557
 f2fs_nfs_get_inode+0x80/0x118 fs/f2fs/super.c:3091
 generic_fh_to_dentry+0x9c/0x104 fs/libfs.c:1044
 f2fs_fh_to_dentry+0x44/0x58 fs/f2fs/super.c:3105
 exportfs_decode_fh_raw+0x114/0x4b4 fs/exportfs/expfs.c:436
 exportfs_decode_fh+0x50/0x80 fs/exportfs/expfs.c:576
 do_handle_to_path fs/fhandle.c:152 [inline]
 handle_to_path fs/fhandle.c:207 [inline]
 do_handle_open+0x5b8/0x9fc fs/fhandle.c:223
 __do_sys_open_by_handle_at fs/fhandle.c:265 [inline]
 __se_sys_open_by_handle_at fs/fhandle.c:256 [inline]
 __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:256
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Allocated by task 3972:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x8c/0xcc mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x74/0x3f4 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x1dc/0x45c mm/slub.c:3233
 f2fs_kmem_cache_alloc_nofail fs/f2fs/f2fs.h:2633 [inline]
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2643 [inline]
 __grab_extent_tree fs/f2fs/extent_cache.c:295 [inline]
 __f2fs_init_extent_tree fs/f2fs/extent_cache.c:381 [inline]
 f2fs_init_extent_tree+0x4c8/0xb70 fs/f2fs/extent_cache.c:404
 do_read_inode fs/f2fs/inode.c:383 [inline]
 f2fs_iget+0x1088/0x53b8 fs/f2fs/inode.c:505
 f2fs_nfs_get_inode+0x80/0x118 fs/f2fs/super.c:3091
 generic_fh_to_dentry+0x9c/0x104 fs/libfs.c:1044
 f2fs_fh_to_dentry+0x44/0x58 fs/f2fs/super.c:3105
 exportfs_decode_fh_raw+0x114/0x4b4 fs/exportfs/expfs.c:436
 exportfs_decode_fh+0x50/0x80 fs/exportfs/expfs.c:576
 do_handle_to_path fs/fhandle.c:152 [inline]
 handle_to_path fs/fhandle.c:207 [inline]
 do_handle_open+0x5b8/0x9fc fs/fhandle.c:223
 __do_sys_open_by_handle_at fs/fhandle.c:265 [inline]
 __se_sys_open_by_handle_at fs/fhandle.c:256 [inline]
 __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:256
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Freed by task 3972:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4c/0x84 mm/kasan/common.c:46
 kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360
 ____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0x128/0x1ec mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0xdc/0x3c4 mm/slub.c:3515
 f2fs_destroy_extent_tree+0x2e0/0x6e0 fs/f2fs/extent_cache.c:845
 f2fs_evict_inode+0x330/0x1564 fs/f2fs/inode.c:758
 evict+0x260/0x68c fs/inode.c:587
 iput_final fs/inode.c:1705 [inline]
 iput+0x744/0x824 fs/inode.c:1731
 iget_failed+0x154/0x1a4 fs/bad_inode.c:250
 f2fs_iget+0x588/0x53b8 fs/f2fs/inode.c:557
 f2fs_nfs_get_inode+0x80/0x118 fs/f2fs/super.c:3091
 generic_fh_to_dentry+0x9c/0x104 fs/libfs.c:1044
 f2fs_fh_to_dentry+0x44/0x58 fs/f2fs/super.c:3105
 exportfs_decode_fh_raw+0x114/0x4b4 fs/exportfs/expfs.c:436
 exportfs_decode_fh+0x50/0x80 fs/exportfs/expfs.c:576
 do_handle_to_path fs/fhandle.c:152 [inline]
 handle_to_path fs/fhandle.c:207 [inline]
 do_handle_open+0x5b8/0x9fc fs/fhandle.c:223
 __do_sys_open_by_handle_at fs/fhandle.c:265 [inline]
 __se_sys_open_by_handle_at fs/fhandle.c:256 [inline]
 __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:256
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the object at ffff0000deced000
 which belongs to the cache f2fs_extent_tree of size 136
The buggy address is located 0 bytes inside of
 136-byte region [ffff0000deced000, ffff0000deced088)
The buggy address belongs to the page:
page:00000000f4f3a067 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11eced
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c6604d80
raw: 0000000000000000 0000000080140014 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000dececf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000dececf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000deced000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff0000deced080: fb fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb
 ffff0000deced100: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/05 13:43 linux-5.15.y 284087d4f7d5 610f2a54 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in f2fs_iget
2024/05/05 12:48 linux-5.15.y 284087d4f7d5 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in f2fs_iget
* Struck through repros no longer work on HEAD.