Tracker / CVE-2026-53223
CVE-2026-53223
In the Linux kernel, the following vulnerability has been resolved: net: guard timestamp cmsgs to real error queue skbs skb_is_err_queue() treats PACKET_OUTGOING as the sole marker for an skb from sk_error_queue. That assumption is not true for AF_PACKET sockets: outgoing packet taps are also delivered to packet sockets with skb->pkt_type == PACKET_OUTGOING, but their skb->cb is owned by AF_PACKET instead of struct sock_exterr_skb. If such an skb is received with timestamping enabled, the generic timestamp cmsg path can read AF_PACKET control-buffer state as sock_exterr_skb::opt_stats. With SO_RXQ_OVFL enabled, the packet drop counter overlaps opt_stats. An odd drop count makes the path emit SCM_TIMESTAMPING_OPT_STATS with skb->len and skb->data. For non-linear skbs this copies past the linear head and can trigger hardened usercopy or disclose adjacent heap contents. Keep skb_is_err_queue() local to net/socket.c, but make it verify that the PACKET_OUTGOING marker is paired with the sock_rmem_free destructor installed by sock_queue_err_skb(). AF_PACKET receive skbs use normal receive ownership and no longer pass as error-queue skbs, while legitimate sk_error_queue entries keep the PACKET_OUTGOING marker and sock_rmem_free ownership.
Affected products and versions
| linux | linux_kernel |
|---|---|
| linux | linux_kernel · 4.10.14 → 4.11 |
| linux | linux_kernel · 4.11.1 → 5.10.259 |
| linux | linux_kernel · 5.11 → 5.15.210 |
| linux | linux_kernel · 5.16 → 6.1.176 |
| linux | linux_kernel · 6.13 → 6.18.36 |
| linux | linux_kernel · 6.19 → 7.0.13 |
| linux | linux_kernel · 6.2 → 6.6.143 |
| linux | linux_kernel · 6.7 → 6.12.94 |