skmsg: Fix wrong last sg check in sk_msg_recvmsg()
Summary
skmsg: Fix wrong last sg check in sk_msg_recvmsg()
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
skmsg: Fix wrong last sg check in sk_msg_recvmsg()
Fix one kernel NULL pointer dereference as below:
[ 224.462334] Call Trace:
[ 224.462394] __tcp_bpf_recvmsg+0xd3/0x380
[ 224.462441] ? sock_has_perm+0x78/0xa0
[ 224.462463] tcp_bpf_recvmsg+0x12e/0x220
[ 224.462494] inet_recvmsg+0x5b/0xd0
[ 224.462534] __sys_recvfrom+0xc8/0x130
[ 224.462574] ? syscall_trace_enter+0x1df/0x2e0
[ 224.462606] ? __do_page_fault+0x2de/0x500
[ 224.462635] __x64_sys_recvfrom+0x24/0x30
[ 224.462660] do_syscall_64+0x5d/0x1d0
[ 224.462709] entry_SYSCALL_64_after_hwframe+0x65/0xca
In commit 9974d37ea75f ("skmsg: Fix invalid last sg check in
sk_msg_recvmsg()"), we change last sg check to sg_is_last(),
but in sockmap redirection case (without stream_parser/stream_verdict/
skb_verdict), we did not mark the end of the scatterlist. Check the
sk_msg_alloc, sk_msg_page_add, and bpf_msg_push_data functions, they all
do not mark the end of sg. They are expected to use sg.end for end
judgment. So the judgment of '(i != msg_rx->sg.end)' is added back here.
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2022-49973 linux Fixed in: 6.0.2-1
- Ubuntu UBUNTU-CVE-2022-49973 linux-hwe-edge
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org