diff options
| author |   Eric Dumazet <edumazet@google.com> | 2025-03-07 07:43:02 +0000 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2025-03-07 19:09:39 -0800 |
| commit | 0a5c8b2c8ccbd5987f5d05c6ad6740cdb2e467e8 (patch) | |
| tree | 6128464c6e9852db83495fb950e1da826431bd6a | |
| parent | Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next (diff) | |
| download | wireguard-linux-0a5c8b2c8ccbd5987f5d05c6ad6740cdb2e467e8.tar.xz wireguard-linux-0a5c8b2c8ccbd5987f5d05c6ad6740cdb2e467e8.zip | |
bpf: fix a possible NULL deref in bpf_map_offload_map_alloc()
Call bpf_dev_offload_check() before netdev_lock_ops().
This is needed if attr->map_ifindex is not valid.
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000197: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000cb8-0x0000000000000cbf]
RIP: 0010:netdev_need_ops_lock include/linux/netdevice.h:2792 [inline]
RIP: 0010:netdev_lock_ops include/linux/netdevice.h:2803 [inline]
RIP: 0010:bpf_map_offload_map_alloc+0x19a/0x910 kernel/bpf/offload.c:533
Call Trace:
<TASK>
map_create+0x946/0x11c0 kernel/bpf/syscall.c:1455
__sys_bpf+0x6d3/0x820 kernel/bpf/syscall.c:5777
__do_sys_bpf kernel/bpf/syscall.c:5902 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5900 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5900
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
Fixes: 97246d6d21c2 ("net: hold netdev instance lock during ndo_bpf")
Reported-by: syzbot+0c7bfd8cf3aecec92708@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/67caa2b1.050a0220.15b4b9.0077.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250307074303.1497911-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | kernel/bpf/offload.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index a10153c3be2d..4f707cfe7f10 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -530,11 +530,12 @@ struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) bpf_map_init_from_attr(&offmap->map, attr); rtnl_lock(); offmap->netdev = __dev_get_by_index(net, attr->map_ifindex); - netdev_lock_ops(offmap->netdev); - down_write(&bpf_devs_lock); err = bpf_dev_offload_check(offmap->netdev); if (err) - goto err_unlock; + goto err_unlock_rtnl; + + netdev_lock_ops(offmap->netdev); + down_write(&bpf_devs_lock); ondev = bpf_offload_find_netdev(offmap->netdev); if (!ondev) { @@ -556,6 +557,7 @@ struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) err_unlock: up_write(&bpf_devs_lock); netdev_unlock_ops(offmap->netdev); +err_unlock_rtnl: rtnl_unlock(); bpf_map_area_free(offmap); return ERR_PTR(err); |