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KASAN: use-after-free Read in __ext4_iget

Status: upstream: reported on 2024/01/31 03:06
Reported-by: syzbot+caaaafd8611645a190df@syzkaller.appspotmail.com
First crash: 295d, last: 23d
▶ ▼ Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in __ext4_iget 2 70d 112d 0/3 upstream: reported on 2024/08/01 05:00
upstream KASAN: slab-use-after-free Read in __ext4_iget fs reiserfs 278 296d 533d 0/28 auto-obsoleted due to no activity on 2024/04/09 13:42
android-5-15 KASAN: use-after-free Read in __ext4_iget origin:lts syz 98 20h59m 512d 0/2 premoderation: reported syz repro on 2023/06/28 10:27
linux-5.15 KASAN: slab-out-of-bounds Read in __ext4_iget 6 400d 443d 0/3 auto-obsoleted due to no activity on 2024/01/25 22:09
android-54 KASAN: use-after-free Read in __ext4_iget 13 272d 479d 0/2 auto-obsoleted due to no activity on 2024/05/22 19:07
android-5-10 KASAN: use-after-free Read in __ext4_iget syz 112 1d23h 512d 0/2 premoderation: reported syz repro on 2023/06/28 15:01
android-54 KASAN: use-after-free Read in __ext4_iget (2) 4 155d 173d 0/2 auto-obsoleted due to no activity on 2024/09/17 10:19
linux-6.1 KASAN: slab-out-of-bounds Read in __ext4_iget 14 234d 490d 0/3 auto-obsoleted due to no activity on 2024/07/09 19:10

Sample crash report:
loop3: detected capacity change from 0 to 1024
EXT4-fs (loop3): Quota format mount options ignored when QUOTA feature is enabled
EXT4-fs (loop3): Quota format mount options ignored when QUOTA feature is enabled
==================================================================
BUG: KASAN: use-after-free in __ext4_iget+0x2ee/0x3f00 fs/ext4/inode.c:4641
Read of size 8 at addr ffff888061cf1a30 by task syz.3.260/5520

CPU: 1 PID: 5520 Comm: syz.3.260 Not tainted 5.15.164-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
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
 __ext4_iget+0x2ee/0x3f00 fs/ext4/inode.c:4641
 ext4_quota_enable fs/ext4/super.c:6387 [inline]
 ext4_enable_quotas+0x54f/0xd40 fs/ext4/super.c:6423
 ext4_fill_super+0x9598/0xa110 fs/ext4/super.c:4959
 mount_bdev+0x2c9/0x3f0 fs/super.c:1387
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1517
 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: 0033:0x7f2b52c290fa
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 7e 1a 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2b51084e68 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2b51084ef0 RCX: 00007f2b52c290fa
RDX: 0000000020000580 RSI: 00000000200005c0 RDI: 00007f2b51084eb0
RBP: 0000000020000580 R08: 00007f2b51084ef0 R09: 0000000001008002
R10: 0000000001008002 R11: 0000000000000202 R12: 00000000200005c0
R13: 00007f2b51084eb0 R14: 00000000000005d8 R15: 0000000020000340
 </TASK>

Allocated by task 4845:
 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+0x8e/0xc0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2640 [inline]
 f2fs_alloc_inode+0x15d/0x5b0 fs/f2fs/super.c:1383
 alloc_inode fs/inode.c:236 [inline]
 iget_locked+0x194/0x7f0 fs/inode.c:1244
 f2fs_iget+0x52/0x4ae0 fs/f2fs/inode.c:495
 f2fs_fill_super+0x6484/0x8350 fs/f2fs/super.c:4258
 mount_bdev+0x2c9/0x3f0 fs/super.c:1387
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1517
 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

Last potentially related work creation:
 kasan_save_stack+0x36/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3007 [inline]
 call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3087
 f2fs_fill_super+0x6907/0x8350 fs/f2fs/super.c:4441
 mount_bdev+0x2c9/0x3f0 fs/super.c:1387
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1517
 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

Second to last potentially related work creation:
 kasan_save_stack+0x36/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3007 [inline]
 call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3087
 f2fs_put_super+0x726/0xd10 fs/f2fs/super.c:1618
 generic_shutdown_super+0x136/0x2c0 fs/super.c:475
 kill_block_super+0x7a/0xe0 fs/super.c:1414
 kill_f2fs_super+0x2ff/0x3c0 fs/f2fs/super.c:4537
 deactivate_locked_super+0xa0/0x110 fs/super.c:335
 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
 task_work_run+0x129/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888061cf1300
 which belongs to the cache f2fs_inode_cache of size 2304
The buggy address is located 1840 bytes inside of
 2304-byte region [ffff888061cf1300, ffff888061cf1c00)
The buggy address belongs to the page:
page:ffffea0001873c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888061cf1300 pfn:0x61cf0
head:ffffea0001873c00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff888023d32501
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888146513dc0
raw: ffff888061cf1300 00000000800d000b 00000001ffffffff ffff888023d32501
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0x1d2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 3648, ts 48207491982, free_ts 10639759147
 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_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2640 [inline]
 f2fs_alloc_inode+0x15d/0x5b0 fs/f2fs/super.c:1383
 alloc_inode fs/inode.c:236 [inline]
 iget_locked+0x194/0x7f0 fs/inode.c:1244
 f2fs_iget+0x52/0x4ae0 fs/f2fs/inode.c:495
 f2fs_fill_super+0x4ef8/0x8350 fs/f2fs/super.c:4150
 mount_bdev+0x2c9/0x3f0 fs/super.c:1387
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1517
 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
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+0x95/0x2d0 mm/page_alloc.c:3396
 free_contig_range+0x95/0xf0 mm/page_alloc.c:9342
 destroy_args+0xfe/0x980 mm/debug_vm_pgtable.c:1018
 debug_vm_pgtable+0x40d/0x470 mm/debug_vm_pgtable.c:1331
 do_one_initcall+0x22b/0x7a0 init/main.c:1302
 do_initcall_level+0x157/0x210 init/main.c:1375
 do_initcalls+0x49/0x90 init/main.c:1391
 kernel_init_freeable+0x425/0x5c0 init/main.c:1615
 kernel_init+0x19/0x290 init/main.c:1506
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff888061cf1900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888061cf1980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888061cf1a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888061cf1a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888061cf1b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/09 17:18 linux-5.15.y 7e89efd3ae1c a83d9288 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ext4_iget
2024/07/21 09:47 linux-5.15.y 7c6d66f0266f b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ext4_iget
2024/04/12 02:14 linux-5.15.y cdfd0a7f0139 27de0a5c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ext4_iget
2024/04/02 00:09 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ext4_iget
2024/01/31 03:05 linux-5.15.y 6139f2a02fe0 7f400fcb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in __ext4_iget
2024/09/16 14:47 linux-5.15.y 3a5928702e71 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ext4_iget
2024/05/30 03:44 linux-5.15.y c61bd26ae81a 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ext4_iget
2024/04/02 00:37 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ext4_iget
2024/04/01 07:28 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ext4_iget
2024/03/29 18:25 linux-5.15.y 9465fef4ae35 c52bcb23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in __ext4_iget
2024/10/29 14:09 linux-5.15.y 74cdd62cb470 66aeb999 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in __ext4_iget
2024/07/08 03:47 linux-5.15.y f45bea23c39c 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in __ext4_iget
* Struck through repros no longer work on HEAD.