From: Eric Dumazet <edumazet@google.com> stable inclusion from stable-v5.10.239 commit f2d1443b18806640abdb530e88009af7be2588e7 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICK4OX CVE: CVE-2025-38180 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit d03b79f459c7935cff830d98373474f440bd03ae ] /proc/net/atm/lec must ensure safety against dev_lec[] changes. It appears it had dev_put() calls without prior dev_hold(), leading to imbalance and UAF. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Francois Romieu <romieu@fr.zoreil.com> # Minor atm contributor Link: https://patch.msgid.link/20250618140844.1686882-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> Reviewed-by: Zhang Changzhong <zhangchangzhong@huaiwei.com> --- net/atm/lec.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/atm/lec.c b/net/atm/lec.c index 97e799635c6c..4fc81eac8c75 100644 --- a/net/atm/lec.c +++ b/net/atm/lec.c @@ -917,7 +917,6 @@ static void *lec_itf_walk(struct lec_state *state, loff_t *l) v = (dev && netdev_priv(dev)) ? lec_priv_walk(state, l, netdev_priv(dev)) : NULL; if (!v && dev) { - dev_put(dev); /* Partial state reset for the next time we get called */ dev = NULL; } @@ -941,6 +940,7 @@ static void *lec_seq_start(struct seq_file *seq, loff_t *pos) { struct lec_state *state = seq->private; + mutex_lock(&lec_mutex); state->itf = 0; state->dev = NULL; state->locked = NULL; @@ -958,8 +958,9 @@ static void lec_seq_stop(struct seq_file *seq, void *v) if (state->dev) { spin_unlock_irqrestore(&state->locked->lec_arp_lock, state->flags); - dev_put(state->dev); + state->dev = NULL; } + mutex_unlock(&lec_mutex); } static void *lec_seq_next(struct seq_file *seq, void *v, loff_t *pos) -- 2.25.1