diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-06-18 14:08:44 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-06-19 08:36:31 -0700 |
| commit | d03b79f459c7935cff830d98373474f440bd03ae (patch) | |
| tree | ca8b1cdb60e6171d95deb5e46b86f65c8e6e868d | |
| parent | d13a3824bfd2b4774b671a75cf766a16637a0e67 (diff) | |
net: atm: fix /proc/net/atm/lec handling
/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>
| -rw-r--r-- | net/atm/lec.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/atm/lec.c b/net/atm/lec.c index 1e1f3eb0e2ba..afb8d3eb2185 100644 --- a/net/atm/lec.c +++ b/net/atm/lec.c @@ -909,7 +909,6 @@ 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; } @@ -933,6 +932,7 @@ 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; @@ -950,8 +950,9 @@ 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) |