syzbot


BUG: unable to handle kernel paging request in nsim_bpf

Status: fixed on 2024/01/20 21:18
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+44c2416196b7c607f226@syzkaller.appspotmail.com
Fix commit: c0c6bde586c7 netdevsim: Don't accept device bound programs
First crash: 230d, last: 211d
Discussions (5)
Title Replies (including bot) Last reply
[PATCH bpf-next 1/2] netdevsim: don't accept device bound programs 3 (3) 2023/11/20 21:58
[PATCH] Fixes the null pointer deferences in nsim_bpf 5 (5) 2023/11/10 19:20
Re: [syzbot] [PATCH] net: Fix the null pointer deference in nsim_setup_prog_hw_checks 0 (1) 2023/11/10 04:44
[syzbot] [net?] BUG: unable to handle kernel paging request in nsim_bpf 1 (2) 2023/11/10 00:21
Re: [syzbot] [PATCH] Fix the null pointer deference in nsim_setup_prog_hw_checks 0 (1) 2023/11/09 19:24
Last patch testing requests (3)
Created Duration User Patch Repo Result
2023/11/19 18:42 17m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2023/11/10 04:44 38m kdipendra88@gmail.com patch https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git 8de1e7afcc1c OK log
2023/11/09 19:24 18m kdipendra88@gmail.com patch https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git 8de1e7afcc1c report log

Sample crash report:
netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
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: 6083 Comm: syz-executor299 Not tainted 6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : nsim_setup_prog_hw_checks drivers/net/netdevsim/bpf.c:320 [inline]
pc : nsim_bpf+0x1e0/0xae0 drivers/net/netdevsim/bpf.c:562
lr : nsim_bpf+0x8c/0xae0 drivers/net/netdevsim/bpf.c:554
sp : ffff800096b97790
x29: ffff800096b977a0 x28: dfff800000000000 x27: ffff700012d72f00
x26: dfff800000000000 x25: ffff800096b97a00 x24: 0000000000000008
x23: ffff800096b97820 x22: 0000000000000018 x21: ffff800096b97820
x20: ffff0000d5e38cc0 x19: ffff0000d5e38000 x18: ffff800096b97580
x17: ffff8000805c1258 x16: ffff80008030c738 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000003
x11: ffff0000d55a3780 x10: 00000000000000bc x9 : ffff800085ce8bf0
x8 : 0000000000000003 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffff800092e2e000 x4 : 0000000000000000 x3 : ffff80008030c754
x2 : 0000000000000000 x1 : ffff80009001ef50 x0 : 0000000000000001
Call trace:
 nsim_setup_prog_hw_checks drivers/net/netdevsim/bpf.c:320 [inline]
 nsim_bpf+0x1e0/0xae0 drivers/net/netdevsim/bpf.c:562
 dev_xdp_install+0x124/0x2f0 net/core/dev.c:9199
 dev_xdp_attach+0xa4c/0xcc8 net/core/dev.c:9351
 dev_xdp_attach_link net/core/dev.c:9370 [inline]
 bpf_xdp_link_attach+0x300/0x710 net/core/dev.c:9540
 link_create+0x2c0/0x68c kernel/bpf/syscall.c:4954
 __sys_bpf+0x4d4/0x5dc kernel/bpf/syscall.c:5414
 __do_sys_bpf kernel/bpf/syscall.c:5448 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5446 [inline]
 __arm64_sys_bpf+0x80/0x98 kernel/bpf/syscall.c:5446
 __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+0x54/0x158 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:595
Code: 96b3720d f94002c8 91006116 d343fec8 (387a6908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	96b3720d 	bl	0xfffffffffacdc834
   4:	f94002c8 	ldr	x8, [x22]
   8:	91006116 	add	x22, x8, #0x18
   c:	d343fec8 	lsr	x8, x22, #3
* 10:	387a6908 	ldrb	w8, [x8, x26] <-- trapping instruction

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/24 19:25 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8de1e7afcc1c 5b429f39 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in nsim_bpf
2023/11/05 05:30 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8de1e7afcc1c 500bfdc4 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in nsim_bpf
2023/11/05 05:02 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8de1e7afcc1c 500bfdc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in nsim_bpf
* Struck through repros no longer work on HEAD.