imrcpan/erofs-linux
1
0 Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git synced 2026-11-02 23:54:33 +01:00
Code Issues Packages Projects Releases Wiki Activity

can: bcm: add missing rcu read protection for procfs content

Browse Source 
When the procfs content is generated for a bcm_op which is in the process
to be removed the procfs output might show unreliable data (UAF).

As the removal of bcm_op's is already implemented with rcu handling this
patch adds the missing rcu_read_lock() and makes sure the list entries
are properly removed under rcu protection.

Fixes: f1b4e32aca ("can: bcm: use call_rcu() instead of costly synchronize_rcu()")
Reported-by: Anderson Nascimento <[email protected]>
Suggested-by: Anderson Nascimento <[email protected]>
Tested-by: Anderson Nascimento <[email protected]>
Signed-off-by: Oliver Hartkopp <[email protected]>
Link: https://patch.msgid.link/[email protected]
Cc: [email protected] # >= 5.4
Signed-off-by: Marc Kleine-Budde <[email protected]>
This commit is contained in:
Oliver Hartkopp authored and Marc Kleine-Budde committed 2025-05-19 16:58:19 +02:00
1 parent c2aba69d0c
commit dac5e62491
1 file changed
+9 -4
Download Patch File Download Diff File Expand all files Collapse all files
net/can/bcm.c
+9 -4
View File
@@ -219,7 +219,9 @@ static int bcm_proc_show(struct seq_file *m, void *v)
seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
seq_printf(m, " <<<\n");
list_for_each_entry(op, &bo->rx_ops, list) {
rcu_read_lock();
list_for_each_entry_rcu(op, &bo->rx_ops, list) {
unsigned long reduction;
@@ -275,6 +277,9 @@ static int bcm_proc_show(struct seq_file *m, void *v)
seq_printf(m, "# sent %ld\n", op->frames_abs);
}
seq_putc(m, '\n');
rcu_read_unlock();
return 0;
}
#endif /* CONFIG_PROC_FS */
@@ -858,7 +863,7 @@ static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
REGMASK(op->can_id),
bcm_rx_handler, op);
list_del(&op->list);
list_del_rcu(&op->list);
bcm_remove_op(op);
return 1; /* done */
}
@@ -878,7 +883,7 @@ static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
list_for_each_entry_safe(op, n, ops, list) {
if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
(op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
list_del(&op->list);
list_del_rcu(&op->list);
bcm_remove_op(op);
return 1; /* done */
}
@@ -1296,7 +1301,7 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
bcm_rx_handler, op, "bcm", sk);
if (err) {
/* this bcm rx op is broken -> remove it */
list_del(&op->list);
list_del_rcu(&op->list);
bcm_remove_op(op);
return err;
}