Description
In the Linux kernel, the following vulnerability has been resolved: net, bpf: check master for NULL in xdp_master_redirect() xdp_master_redirect() dereferences the result of netdev_master_upper_dev_get_rcu() without a NULL check, but that helper returns NULL when the receiving device has no upper-master adjacency. The reach guard only checks netif_is_bond_slave(). On bond slave release bond_upper_dev_unlink() drops the upper-master adjacency before clearing IFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window still passes netif_is_bond_slave() while master is already NULL, and faults on master->flags at offset 0xb0: BUG: kernel NULL pointer dereference, address: 00000000000000b0 RIP: 0010:xdp_master_redirect (net/core/filter.c:4432) Call Trace: xdp_master_redirect (net/core/filter.c:4432) bpf_prog_run_generic_xdp (include/net/xdp.h:700) do_xdp_generic (net/core/dev.c:5608) __netif_receive_skb_one_core (net/core/dev.c:6204) process_backlog (net/core/dev.c:6319) __napi_poll (net/core/dev.c:7729) net_rx_action (net/core/dev.c:7792) handle_softirqs (kernel/softirq.c:622) __dev_queue_xmit (include/linux/bottom_half.h:33) packet_sendmsg (net/packet/af_packet.c:3082) __sys_sendto (net/socket.c:2252) Kernel panic - not syncing: Fatal exception in interrupt The missing check dates back to the original code; commit 1921f91298d1 ("net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master") later added the master->flags read where the fault now lands but kept the unconditional deref. Check master for NULL before use; a NULL master is treated the same as one that is not up.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 to < c99ca049e910d61ddbd28cc2c47242f2bfbb4970affected879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 to < e2a56441233131fe18a76001de347ecda217e40caffected879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 to < 3876318ea54e83eb70982b8280a3c5e4e32269bfaffected879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 to < 4edbcacca09f92b85d3951b6add11894b20a84bcaffected879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 to < 03b743586a2469744e96e9c1015096d07240935daffected879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 to < 89c103d702b25ceb2d097faf854deb47b53b17ffaffected879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 to < e82d8cc4321c373dc46e741cd2dfdaa7921fddb7affected
Linux Linux
Default version status: affected
5.15affected0 to < 5.15unaffected5.15.212 to ≤ 5.15.*unaffected6.1.178 to ≤ 6.1.*unaffected6.6.145 to ≤ 6.6.*unaffected6.12.97 to ≤ 6.12.*unaffected6.18.40 to ≤ 6.18.*unaffected7.1.5 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/c99ca049e910d61ddbd28cc2c47242f2bfbb4970 ↗
- https://git.kernel.org/stable/c/e2a56441233131fe18a76001de347ecda217e40c ↗
- https://git.kernel.org/stable/c/3876318ea54e83eb70982b8280a3c5e4e32269bf ↗
- https://git.kernel.org/stable/c/4edbcacca09f92b85d3951b6add11894b20a84bc ↗
- https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d ↗
- https://git.kernel.org/stable/c/89c103d702b25ceb2d097faf854deb47b53b17ff ↗
- https://git.kernel.org/stable/c/e82d8cc4321c373dc46e741cd2dfdaa7921fddb7 ↗
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html ↗
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html ↗