syzbot


KASAN: slab-out-of-bounds Read in ext4_search_dir

Status: upstream: reported C repro on 2023/11/17 09:38
Reported-by: syzbot+ac107c9fba66d9b8ad08@syzkaller.appspotmail.com
First crash: 211d, last: 47d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: slab-out-of-bounds Read in ext4_search_dir origin:upstream C 2 30d 211d 0/2 upstream: reported C repro on 2023/11/17 09:38
upstream KASAN: use-after-free Read in ext4_search_dir prio:low ext4 C error done 20 160d 401d 26/27 fixed on 2024/02/21 18:23
linux-5.15 KASAN: use-after-free Read in ext4_search_dir origin:upstream C 1 27d 365d 0/3 upstream: reported C repro on 2023/06/16 15:52
android-54 KASAN: use-after-free Read in ext4_search_dir C 17 17d 61d 0/2 upstream: reported C repro on 2024/04/15 06:47
android-6-1 KASAN: use-after-free Read in ext4_search_dir origin:upstream C error 10 14d 237d 0/2 upstream: reported C repro on 2023/10/22 16:55
linux-6.1 KASAN: use-after-free Read in ext4_search_dir origin:upstream C 1 25d 363d 0/3 upstream: reported C repro on 2023/06/18 19:29
Last patch testing requests (2)
Created Duration User Patch Repo Result
2024/04/29 09:09 8m retest repro android13-5.10-lts report log
2023/12/01 09:38 8m retest repro android13-5.10-lts report log
Fix bisection attempts (5)
Created Duration User Patch Repo Result
2024/05/30 18:28 6m bisect fix android13-5.10-lts error job log (0)
2024/04/06 20:03 1h02m bisect fix android13-5.10-lts job log (0) log
2024/03/06 22:56 37m bisect fix android13-5.10-lts job log (0) log
2024/02/03 06:35 36m bisect fix android13-5.10-lts job log (0) log
2023/12/31 11:12 35m bisect fix android13-5.10-lts job log (0) log

Sample crash report:
EXT4-fs (loop0): Ignoring removed bh option
EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
EXT4-fs (loop0): 1 truncate cleaned up
EXT4-fs (loop0): mounted filesystem without journal. Opts: jqfmt=vfsold,resgid=0x000000000000ee00,bh,noload,data_err=ignore,usrjquota=,,errors=continue
==================================================================
BUG: KASAN: slab-out-of-bounds in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1515
Read of size 1 at addr ffff88811e3b7d23 by task syz-executor203/291

CPU: 0 PID: 291 Comm: syz-executor203 Not tainted 5.10.199-syzkaller-00307-gd30b996835c0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:452
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1515
 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1700
 __ext4_find_entry+0x2b0/0x1990 fs/ext4/namei.c:1588
 ext4_lookup_entry fs/ext4/namei.c:1743 [inline]
 ext4_lookup+0x3c6/0xaa0 fs/ext4/namei.c:1811
 __lookup_hash+0x143/0x290 fs/namei.c:1541
 filename_create+0x202/0x750 fs/namei.c:3614
 user_path_create fs/namei.c:3671 [inline]
 do_mkdirat+0xcc/0x2c0 fs/namei.c:3811
 __do_sys_mkdirat fs/namei.c:3829 [inline]
 __se_sys_mkdirat fs/namei.c:3827 [inline]
 __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3827
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7f27e5470539
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 1c 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:00007fffbc113a88 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f27e5470539
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 00000000ffffff9c
RBP: 00007fffbc113b70 R08: 00000000000014ef R09: 00007f27e54b44ee
R10: 00000000000014f3 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fffbc113b40 R14: 0000000000000001 R15: 00007fffbc113b70

Allocated by task 0:
(stack is not available)

Freed by task 291:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x121/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1595 [inline]
 slab_free_freelist_hook+0xc0/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kfree+0xc3/0x270 mm/slub.c:4191
 skb_free_head net/core/skbuff.c:605 [inline]
 skb_release_data+0x5c6/0x6f0 net/core/skbuff.c:625
 skb_release_all net/core/skbuff.c:679 [inline]
 __kfree_skb net/core/skbuff.c:693 [inline]
 consume_skb+0xac/0x250 net/core/skbuff.c:850
 netlink_broadcast_filtered+0x114e/0x1270 net/netlink/af_netlink.c:1532
 netlink_broadcast net/netlink/af_netlink.c:1554 [inline]
 nlmsg_multicast include/net/netlink.h:1033 [inline]
 nlmsg_notify+0x101/0x1c0 net/netlink/af_netlink.c:2540
 rtnl_notify+0x9c/0xd0 net/core/rtnetlink.c:737
 inet6_rt_notify+0x3c8/0x550 net/ipv6/route.c:6059
 fib6_add_rt2node net/ipv6/ip6_fib.c:1249 [inline]
 fib6_add+0x233e/0x3d20 net/ipv6/ip6_fib.c:1475
 __ip6_ins_rt net/ipv6/route.c:1300 [inline]
 ip6_route_add+0x8a/0x130 net/ipv6/route.c:3761
 addrconf_prefix_route net/ipv6/addrconf.c:2442 [inline]
 addrconf_add_linklocal+0x5b5/0x9e0 net/ipv6/addrconf.c:3233
 addrconf_addr_gen+0x572/0xd00 net/ipv6/addrconf.c:3362
 addrconf_dev_config+0x342/0x5a0 net/ipv6/addrconf.c:3414
 addrconf_notify+0x8c5/0xe90 net/ipv6/addrconf.c:3647
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:410
 __dev_notify_flags+0x304/0x610
 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8582
 do_setlink+0xc5c/0x3c10 net/core/rtnetlink.c:2729
 __rtnl_newlink net/core/rtnetlink.c:3407 [inline]
 rtnl_newlink+0x15f0/0x2000 net/core/rtnetlink.c:3527
 rtnetlink_rcv_msg+0x955/0xc50 net/core/rtnetlink.c:5608
 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2497
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5626
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x8df/0xac0 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0xa46/0xd00 net/netlink/af_netlink.c:1916
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 __sys_sendto+0x545/0x700 net/socket.c:2004
 __do_sys_sendto net/socket.c:2016 [inline]
 __se_sys_sendto net/socket.c:2012 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:2012
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6

The buggy address belongs to the object at ffff88811e3b7800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 291 bytes to the right of
 1024-byte region [ffff88811e3b7800, ffff88811e3b7c00)
The buggy address belongs to the page:
page:ffffea000478ec00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11e3b0
head:ffffea000478ec00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042f00
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 291, ts 31169733393, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x166/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5346
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x80/0x400 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x302/0x4b0 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 __kmalloc_track_caller+0x1f8/0x320 mm/slub.c:4536
 __kmalloc_reserve net/core/skbuff.c:143 [inline]
 __alloc_skb+0xbc/0x510 net/core/skbuff.c:211
 alloc_skb include/linux/skbuff.h:1126 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 rtmsg_fib+0x5de/0xbf0 net/ipv4/fib_semantics.c:522
 fib_table_insert+0x1096/0x1eb0 net/ipv4/fib_trie.c:1354
 fib_magic net/ipv4/fib_frontend.c:1093 [inline]
 fib_add_ifaddr+0x10ae/0x1a40 net/ipv4/fib_frontend.c:1139
 fib_netdev_event+0x235/0x5d0 net/ipv4/fib_frontend.c:1477
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:410
 __dev_notify_flags+0x304/0x610
 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8582
 do_setlink+0xc5c/0x3c10 net/core/rtnetlink.c:2729
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88811e3b7c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811e3b7c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88811e3b7d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff88811e3b7d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811e3b7e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
EXT4-fs error (device loop0): ext4_find_dest_de:2076: 

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/17 09:36 android13-5.10-lts d30b996835c0 cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-android-5-10 KASAN: slab-out-of-bounds Read in ext4_search_dir
2024/04/15 07:06 android13-5.10-lts 4e1bc8d8e8ae c8349e48 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 KASAN: use-after-free Read in ext4_search_dir
* Struck through repros no longer work on HEAD.