diff options
| author | Xiang Mei <xmei5@asu.edu> | 2026-03-17 03:50:34 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-03-19 04:05:40 +0300 |
| commit | 605b52497bf89b3b154674deb135da98f916e390 (patch) | |
| tree | dd9f0393dc72c362c0e12f72f9a8aceb4a664f02 /drivers | |
| parent | b3a6df291fecf5f8a308953b65ca72b7fc9e015d (diff) | |
| download | linux-605b52497bf89b3b154674deb135da98f916e390.tar.xz | |
net: bonding: fix NULL deref in bond_debug_rlb_hash_show
rlb_clear_slave intentionally keeps RLB hash-table entries on
the rx_hashtbl_used_head list with slave set to NULL when no
replacement slave is available. However, bond_debug_rlb_hash_show
visites client_info->slave without checking if it's NULL.
Other used-list iterators in bond_alb.c already handle this NULL-slave
state safely:
- rlb_update_client returns early on !client_info->slave
- rlb_req_update_slave_clients, rlb_clear_slave, and rlb_rebalance
compare slave values before visiting
- lb_req_update_subnet_clients continues if slave is NULL
The following NULL deref crash can be trigger in
bond_debug_rlb_hash_show:
[ 1.289791] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 1.292058] RIP: 0010:bond_debug_rlb_hash_show (drivers/net/bonding/bond_debugfs.c:41)
[ 1.293101] RSP: 0018:ffffc900004a7d00 EFLAGS: 00010286
[ 1.293333] RAX: 0000000000000000 RBX: ffff888102b48200 RCX: ffff888102b48204
[ 1.293631] RDX: ffff888102b48200 RSI: ffffffff839daad5 RDI: ffff888102815078
[ 1.293924] RBP: ffff888102815078 R08: ffff888102b4820e R09: 0000000000000000
[ 1.294267] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888100f929c0
[ 1.294564] R13: ffff888100f92a00 R14: 0000000000000001 R15: ffffc900004a7ed8
[ 1.294864] FS: 0000000001395380(0000) GS:ffff888196e75000(0000) knlGS:0000000000000000
[ 1.295239] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1.295480] CR2: 0000000000000000 CR3: 0000000102adc004 CR4: 0000000000772ef0
[ 1.295897] Call Trace:
[ 1.296134] seq_read_iter (fs/seq_file.c:231)
[ 1.296341] seq_read (fs/seq_file.c:164)
[ 1.296493] full_proxy_read (fs/debugfs/file.c:378 (discriminator 1))
[ 1.296658] vfs_read (fs/read_write.c:572)
[ 1.296981] ksys_read (fs/read_write.c:717)
[ 1.297132] do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[ 1.297325] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Add a NULL check and print "(none)" for entries with no assigned slave.
Fixes: caafa84251b88 ("bonding: add the debugfs interface to see RLB hash table")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Link: https://patch.msgid.link/20260317005034.1888794-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/bonding/bond_debugfs.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/net/bonding/bond_debugfs.c b/drivers/net/bonding/bond_debugfs.c index 8adbec7c5084..8967b65f6d84 100644 --- a/drivers/net/bonding/bond_debugfs.c +++ b/drivers/net/bonding/bond_debugfs.c @@ -34,11 +34,17 @@ static int bond_debug_rlb_hash_show(struct seq_file *m, void *v) for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->used_next) { client_info = &(bond_info->rx_hashtbl[hash_index]); - seq_printf(m, "%-15pI4 %-15pI4 %-17pM %s\n", - &client_info->ip_src, - &client_info->ip_dst, - &client_info->mac_dst, - client_info->slave->dev->name); + if (client_info->slave) + seq_printf(m, "%-15pI4 %-15pI4 %-17pM %s\n", + &client_info->ip_src, + &client_info->ip_dst, + &client_info->mac_dst, + client_info->slave->dev->name); + else + seq_printf(m, "%-15pI4 %-15pI4 %-17pM (none)\n", + &client_info->ip_src, + &client_info->ip_dst, + &client_info->mac_dst); } spin_unlock_bh(&bond->mode_lock); |