github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-10-04 02:09:03 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

mctp: route: iterate socket tag list in mctp_lookup_prealloc_tag()

Browse Source 
When a socket transmits a packet with MCTP_TAG_PREALLOC set,
mctp_lookup_prealloc_tag() iterates over the per-netns &mns->keys list
and matches netid, req_tag, peer_addr, and manual_alloc, without
checking whether tmp->sk == &msk->sk. This allows any MCTP socket in the
same network namespace to use and consume another socket's preallocated
tag.

Iterate the socket's own tag list (&msk->keys via sklist) instead of the
namespace-wide &mns->keys list in mctp_lookup_prealloc_tag(), ensuring
that only tags allocated by msk are matched.

Tested in QEMU against Linux 7.3.0-rc3 by allocating a manual tag
(0x18) on socket A via SIOCMCTPALLOCTAG for peer EID 9 and sending a
4-byte message with MCTP_TAG_PREALLOC from socket B in the same network
namespace. On the unfixed kernel, sendto(sock_b) using socket A's
preallocated tag succeeds (ret = 4); with this patch applied,
sendto(sock_b) fails with -ENOENT (errno = 2) while sendto(sock_a)
succeeds (ret = 4).

Fixes: 63ed1aab3d ("mctp: Add SIOCMCTP{ALLOC,DROP}TAG ioctls for tag control")
Suggested-by: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: stable@vger.kernel.org
Signed-off-by: Hui Peng <benquike@gmail.com>
Link: https://patch.msgid.link/20260921051002.1656692-1-benquike@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Hui Peng 2026-09-21 05:10:01 +00:00 committed by Jakub Kicinski
parent 0b2bbfee2b
commit 26cc0e69cc
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/mctp/route.c
View File

@ -825,7 +825,7 @@ static struct mctp_sk_key *mctp_lookup_prealloc_tag(struct mctp_sock *msk,
spin_lock_irqsave(&mns->keys_lock, flags);
hlist_for_each_entry(tmp, &mns->keys, hlist) {
hlist_for_each_entry(tmp, &msk->keys, sklist) {
if (tmp->net != netid)
continue;