syzbot


KASAN: use-after-free Read in tcindex_dump

Status: auto-obsoleted due to no activity on 2023/03/03 20:07
Reported-by: syzbot+b3b40385fc5b156c87db@syzkaller.appspotmail.com
First crash: 590d, last: 531d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 KASAN: use-after-free Read in tcindex_dump 1 1500d 1500d 0/1 auto-closed as invalid on 2020/07/07 00:51
upstream KASAN: use-after-free Read in tcindex_dump net syz 1 1501d 1499d 15/26 fixed on 2020/05/10 10:42

Sample crash report:
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'.
==================================================================
BUG: KASAN: use-after-free in tcindex_dump+0xbea/0xbf0 net/sched/cls_tcindex.c:637
Read of size 8 at addr ffff888090ad42a0 by task syz-executor.0/9629

CPU: 1 PID: 9629 Comm: syz-executor.0 Not tainted 4.14.298-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
 tcindex_dump+0xbea/0xbf0 net/sched/cls_tcindex.c:637
 tcf_fill_node+0x529/0x810 net/sched/cls_api.c:453
 tfilter_notify+0x11c/0x240 net/sched/cls_api.c:476
 tc_ctl_tfilter+0x11af/0x1c10 net/sched/cls_api.c:743
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4322
 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2454
 netlink_unicast_kernel net/netlink/af_netlink.c:1296 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1322
 netlink_sendmsg+0x648/0xbc0 net/netlink/af_netlink.c:1893
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x326/0x800 net/socket.c:2062
 __sys_sendmmsg+0x129/0x330 net/socket.c:2152
 SYSC_sendmmsg net/socket.c:2183 [inline]
 SyS_sendmmsg+0x2f/0x50 net/socket.c:2178
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3

Allocated by task 9629:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15a/0x400 mm/slab.c:3729
 kmalloc_array include/linux/slab.h:607 [inline]
 kcalloc include/linux/slab.h:618 [inline]
 tcindex_alloc_perfect_hash+0x53/0x3c0 net/sched/cls_tcindex.c:299
 tcindex_set_parms+0x13fd/0x17c0 net/sched/cls_tcindex.c:428
 tcindex_change+0x1c1/0x2c0 net/sched/cls_tcindex.c:539
 tc_ctl_tfilter+0xb54/0x1c10 net/sched/cls_api.c:738
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4322
 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2454
 netlink_unicast_kernel net/netlink/af_netlink.c:1296 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1322
 netlink_sendmsg+0x648/0xbc0 net/netlink/af_netlink.c:1893
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x326/0x800 net/socket.c:2062
 __sys_sendmmsg+0x129/0x330 net/socket.c:2152
 SYSC_sendmmsg net/socket.c:2183 [inline]
 SyS_sendmmsg+0x2f/0x50 net/socket.c:2178
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3

Freed by task 17:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 mm/slab.c:3815
 __tcindex_partial_destroy+0x2e/0x50 net/sched/cls_tcindex.c:282
 __rcu_reclaim kernel/rcu/rcu.h:195 [inline]
 rcu_do_batch kernel/rcu/tree.c:2699 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
 rcu_process_callbacks+0x780/0x1180 kernel/rcu/tree.c:2946
 __do_softirq+0x24d/0x9ff kernel/softirq.c:288

The buggy address belongs to the object at ffff888090ad4280
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 32 bytes inside of
 8192-byte region [ffff888090ad4280, ffff888090ad6280)
The buggy address belongs to the page:
page:ffffea000242b500 count:1 mapcount:0 mapping:ffff888090ad4280 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffff888090ad4280 0000000000000000 0000000100000001
raw: ffffea00024eec20 ffffea00019cd220 ffff88813fe65080 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888090ad4180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888090ad4200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888090ad4280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888090ad4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888090ad4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/11/03 20:07 linux-4.14.y a901bb6c7db7 7a2ebf95 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 KASAN: use-after-free Read in tcindex_dump
2022/09/05 13:44 linux-4.14.y 65640c873dcf 922294ab .config console log report info [disk image] [vmlinux] ci2-linux-4-14 KASAN: use-after-free Read in tcindex_dump
* Struck through repros no longer work on HEAD.