syzbot


BUG: unable to handle kernel NULL pointer dereference in bq_xmit_all (2)

Status: upstream: reported on 2024/10/29 09:51
Reported-by: syzbot+c5aa8700c2360f79e13a@syzkaller.appspotmail.com
First crash: 40d, last: 12d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 BUG: unable to handle kernel NULL pointer dereference in bq_xmit_all 19 43d 187d 0/3 upstream: reported on 2024/06/04 09:15
linux-5.15 BUG: unable to handle kernel NULL pointer dereference in bq_xmit_all 3 143d 202d 0/3 auto-obsoleted due to no activity on 2024/10/26 12:47
upstream KASAN: slab-use-after-free Read in bq_xmit_all bpf net C done 29 128d 142d 27/28 fixed on 2024/08/23 02:59

Sample crash report:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
  ESR = 0x0000000086000006
  EC = 0x21: IABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
user pgtable: 4k pages, 48-bit VAs, pgdp=000000012cc47000
[0000000000000000] pgd=0800000113686003, p4d=0800000113686003, pud=08000001124cd003, pmd=0000000000000000
Internal error: Oops: 0000000086000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4665 Comm: syz.1.156 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : 0x0
lr : bond_xdp_xmit+0x310/0x4f4 drivers/net/bonding/bond_main.c:5227
sp : ffff8000208a72a0
x29: ffff8000208a73e0 x28: 1ffff00004114e72 x27: 1ffff00004114e6e
x26: dfff800000000000 x25: ffff0000d7fc0000 x24: ffff8000208a7360
x23: ffff8000208a7340 x22: ffff800012b2f7b8 x21: fffffbffeffb7d48
x20: ffff0000c1f98140 x19: 0000000000000000 x18: 0000000000000200
x17: 0000000000000002 x16: ffff8000082eada8 x15: 0000000000000001
x14: ffff0000dada9b40 x13: 0000000000ff0100 x12: 0000000000080000
x11: 000000000000047a x10: ffff8000217cc000 x9 : 000000000000047b
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000001
x2 : ffff8000208a7340 x1 : 0000000000000001 x0 : ffff0000d7fc0000
Call trace:
 0x0
 bq_xmit_all+0xd20/0x1140 kernel/bpf/devmap.c:391
 __dev_flush+0xc8/0x1a0 kernel/bpf/devmap.c:421
 xdp_do_flush+0x14/0x28 net/core/filter.c:3954
 tun_build_skb drivers/net/tun.c:1703 [inline]
 tun_get_user+0x27d8/0x3774 drivers/net/tun.c:1797
 tun_chr_write_iter+0xfc/0x20c drivers/net/tun.c:2019
 call_write_iter include/linux/fs.h:2174 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x884/0xb44 fs/read_write.c:594
 ksys_write+0x15c/0x26c fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: bad PC value
---[ end trace db02cf1e61580750 ]---

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/26 01:52 linux-5.15.y 0a51d2d4527b 11dbc254 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: unable to handle kernel NULL pointer dereference in bq_xmit_all
2024/10/29 09:50 linux-5.15.y 74cdd62cb470 66aeb999 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: unable to handle kernel NULL pointer dereference in bq_xmit_all
* Struck through repros no longer work on HEAD.