syzbot


BUG: unable to handle kernel paging request in handshake_nl_done_doit

Status: fixed on 2023/10/12 12:48
Subsystems: tls
[Documentation on labels]
Fix commit: 82ba0ff7bf04 net/handshake: fix null-ptr-deref in handshake_nl_done_doit()
First crash: 297d, last: 297d

Sample crash report:
Unable to handle kernel paging request at virtual address dfff800000000003
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
Mem abort info:
  ESR = 0x0000000096000005
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x05: level 1 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[dfff800000000003] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 5986 Comm: syz-executor292 Not tainted 6.5.0-rc7-syzkaller-gfe4469582053 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : handshake_nl_done_doit+0x198/0x9c8 net/handshake/netlink.c:193
lr : handshake_nl_done_doit+0x180/0x9c8
sp : ffff800096e37180
x29: ffff800096e37200 x28: 1ffff00012dc6e34 x27: dfff800000000000
x26: ffff800096e373d0 x25: 0000000000000000 x24: 00000000ffffffa8
x23: ffff800096e373f0 x22: 1ffff00012dc6e38 x21: 0000000000000000
x20: ffff800096e371c0 x19: 0000000000000018 x18: 0000000000000000
x17: 0000000000000000 x16: ffff800080516cc4 x15: 0000000000000001
x14: 1fffe0001b14aa3b x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000003
x8 : 0000000000000003 x7 : ffff800080afe47c x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080a88078
x2 : 0000000000000001 x1 : 00000000ffffffa8 x0 : 0000000000000000
Call trace:
 handshake_nl_done_doit+0x198/0x9c8 net/handshake/netlink.c:193
 genl_family_rcv_msg_doit net/netlink/genetlink.c:970 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1050 [inline]
 genl_rcv_msg+0x96c/0xc50 net/netlink/genetlink.c:1067
 netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2549
 genl_rcv+0x38/0x50 net/netlink/genetlink.c:1078
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:725 [inline]
 sock_sendmsg net/socket.c:748 [inline]
 ____sys_sendmsg+0x56c/0x840 net/socket.c:2494
 ___sys_sendmsg net/socket.c:2548 [inline]
 __sys_sendmsg+0x26c/0x33c net/socket.c:2577
 __do_sys_sendmsg net/socket.c:2586 [inline]
 __se_sys_sendmsg net/socket.c:2584 [inline]
 __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2584
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x58/0x16c arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
Code: 12800108 b90043e8 910062b3 d343fe68 (387b6908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	12800108 	mov	w8, #0xfffffff7            	// #-9
   4:	b90043e8 	str	w8, [sp, #64]
   8:	910062b3 	add	x19, x21, #0x18
   c:	d343fe68 	lsr	x8, x19, #3
* 10:	387b6908 	ldrb	w8, [x8, x27] <-- trapping instruction

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/27 23:29 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe4469582053 03d9c195 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in handshake_nl_done_doit
2023/08/27 23:09 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe4469582053 03d9c195 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in handshake_nl_done_doit
* Struck through repros no longer work on HEAD.