mirror of
https://git.proxmox.com/git/mirror_ubuntu-kernels.git
synced 2026-01-26 22:58:51 +00:00
09d88791c7
The bpf_redirect_info is shared between the SKB and XDP redirect paths,
and the two paths use the same numeric flag values in the ri->flags
field (specifically, BPF_F_BROADCAST == BPF_F_NEXTHOP). This means that
if skb bpf_redirect_neigh() is used with a non-NULL params argument and,
subsequently, an XDP redirect is performed using the same
bpf_redirect_info struct, the XDP path will get confused and end up
crashing, which syzbot managed to trigger.
With the stack-allocated bpf_redirect_info, the structure is no longer
shared between the SKB and XDP paths, so the crash doesn't happen
anymore. However, different code paths using identically-numbered flag
values in the same struct field still seems like a bit of a mess, so
this patch cleans that up by moving the flag definitions together and
redefining the three flags in BPF_F_REDIRECT_INTERNAL to not overlap
with the flags used for XDP. It also adds a BUILD_BUG_ON() check to make
sure the overlap is not re-introduced by mistake.
Fixes:
|
||
|---|---|---|
| .. | ||
| asm-generic | ||
| drm | ||
| linux | ||
| misc | ||
| mtd | ||
| rdma | ||
| regulator | ||
| scsi | ||
| sound | ||
| video | ||
| xen | ||
| Kbuild | ||