net/x25: Fix potential double free of skb

When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at
line 48 and returns 1 (error).
This error propagates back through the call chain:

x25_queue_rx_frame returns 1
    |
    v
x25_state3_machine receives the return value 1 and takes the else
branch at line 278, setting queued=0 and returning 0
    |
    v
x25_process_rx_frame returns queued=0
    |
    v
x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb)
again

This would free the same skb twice. Looking at x25_backlog_rcv:

net/x25/x25_in.c:x25_backlog_rcv() {
    ...
    queued = x25_process_rx_frame(sk, skb);
    ...
    if (!queued)
        kfree_skb(skb);
}

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Link: https://patch.msgid.link/20260331-x25_fraglen-v4-1-3e69f18464b4@dev.tdt.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

0 files changed, 0 insertions, 0 deletions