diff options
| author |   Xu Kuohai <xukuohai@huawei.com> | 2022-07-28 07:40:48 -0400 |
|---|---|---|
| committer |   Andrii Nakryiko <andrii@kernel.org> | 2022-07-29 14:42:09 -0700 |
| commit | 3b317abc71598bda8ff9a9c483ad8ae167b18382 (patch) | |
| tree | 3c8a72ca4ffad2acab4b78e4d11315cecba80e04 /tools/lib/bpf/libbpf.map | |
| parent | bpf: Fix test_progs -j error with fentry/fexit tests (diff) | |
| download | linux-dev-3b317abc71598bda8ff9a9c483ad8ae167b18382.tar.xz linux-dev-3b317abc71598bda8ff9a9c483ad8ae167b18382.zip | |
bpf: Fix NULL pointer dereference when registering bpf trampoline
A panic was reported on arm64:
[ 44.517109] audit: type=1334 audit(1658859870.268:59): prog-id=19 op=LOAD
[ 44.622031] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000010
[ 44.624321] Mem abort info:
[ 44.625049] ESR = 0x0000000096000004
[ 44.625935] EC = 0x25: DABT (current EL), IL = 32 bits
[ 44.627182] SET = 0, FnV = 0
[ 44.627930] EA = 0, S1PTW = 0
[ 44.628684] FSC = 0x04: level 0 translation fault
[ 44.629788] Data abort info:
[ 44.630474] ISV = 0, ISS = 0x00000004
[ 44.631362] CM = 0, WnR = 0
[ 44.632041] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000100ab5000
[ 44.633494] [0000000000000010] pgd=0000000000000000, p4d=0000000000000000
[ 44.635202] Internal error: Oops: 96000004 [#1] SMP
[ 44.636452] Modules linked in: xfs crct10dif_ce ghash_ce virtio_blk
virtio_console virtio_mmio qemu_fw_cfg
[ 44.638713] CPU: 2 PID: 1 Comm: systemd Not tainted 5.19.0-rc7 #1
[ 44.640164] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[ 44.641799] pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 44.643404] pc : ftrace_set_filter_ip+0x24/0xa0
[ 44.644659] lr : bpf_trampoline_update.constprop.0+0x428/0x4a0
[ 44.646118] sp : ffff80000803b9f0
[ 44.646950] x29: ffff80000803b9f0 x28: ffff0b5d80364400 x27: ffff80000803bb48
[ 44.648721] x26: ffff8000085ad000 x25: ffff0b5d809d2400 x24: 0000000000000000
[ 44.650493] x23: 00000000ffffffed x22: ffff0b5dd7ea0900 x21: 0000000000000000
[ 44.652279] x20: 0000000000000000 x19: 0000000000000000 x18: ffffffffffffffff
[ 44.654067] x17: 0000000000000000 x16: 0000000000000000 x15: ffffffffffffffff
[ 44.655787] x14: ffff0b5d809d2498 x13: ffff0b5d809d2432 x12: 0000000005f5e100
[ 44.657535] x11: abcc77118461cefd x10: 000000000000005f x9 : ffffa7219cb5b190
[ 44.659254] x8 : ffffa7219c8e0000 x7 : 0000000000000000 x6 : ffffa7219db075e0
[ 44.661066] x5 : ffffa7219d3130e0 x4 : ffffa7219cab9da0 x3 : 0000000000000000
[ 44.662837] x2 : 0000000000000000 x1 : ffffa7219cb7a5c0 x0 : 0000000000000000
[ 44.664675] Call trace:
[ 44.665274] ftrace_set_filter_ip+0x24/0xa0
[ 44.666327] bpf_trampoline_update.constprop.0+0x428/0x4a0
[ 44.667696] __bpf_trampoline_link_prog+0xcc/0x1c0
[ 44.668834] bpf_trampoline_link_prog+0x40/0x64
[ 44.669919] bpf_tracing_prog_attach+0x120/0x490
[ 44.671011] link_create+0xe0/0x2b0
[ 44.671869] __sys_bpf+0x484/0xd30
[ 44.672706] __arm64_sys_bpf+0x30/0x40
[ 44.673678] invoke_syscall+0x78/0x100
[ 44.674623] el0_svc_common.constprop.0+0x4c/0xf4
[ 44.675783] do_el0_svc+0x38/0x4c
[ 44.676624] el0_svc+0x34/0x100
[ 44.677429] el0t_64_sync_handler+0x11c/0x150
[ 44.678532] el0t_64_sync+0x190/0x194
[ 44.679439] Code: 2a0203f4 f90013f5 2a0303f5 f9001fe1 (f9400800)
[ 44.680959] ---[ end trace 0000000000000000 ]---
[ 44.682111] Kernel panic - not syncing: Oops: Fatal exception
[ 44.683488] SMP: stopping secondary CPUs
[ 44.684551] Kernel Offset: 0x2721948e0000 from 0xffff800008000000
[ 44.686095] PHYS_OFFSET: 0xfffff4a380000000
[ 44.687144] CPU features: 0x010,00022811,19001080
[ 44.688308] Memory Limit: none
[ 44.689082] ---[ end Kernel panic - not syncing: Oops: Fatal exception ]---
It's caused by a NULL tr->fops passed to ftrace_set_filter_ip(). tr->fops
is initialized to NULL and is assigned to an allocated memory address if
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is enabled. Since there is no
direct call on arm64 yet, the config can't be enabled.
To fix it, call ftrace_set_filter_ip() only if tr->fops is not NULL.
Fixes: 00963a2e75a8 ("bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)")
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Bruno Goncalves <bgoncalv@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20220728114048.3540461-1-xukuohai@huaweicloud.com
Diffstat (limited to '')
0 files changed, 0 insertions, 0 deletions