4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sam Sun <samsun1006219@xxxxxxxxx>
[ Upstream commit e271ff53807e8f2c628758290f0e499dbe51cb3d ]
In function bond_option_arp_ip_targets_set(), if newval->string is an
empty string, newval->string+1 will point to the byte after the
string, causing an out-of-bound read.
BUG: KASAN: slab-out-of-bounds in strlen+0x7d/0xa0 lib/string.c:418
Read of size 1 at addr ffff8881119c4781 by task syz-executor665/8107
CPU: 1 PID: 8107 Comm: syz-executor665 Not tainted 6.7.0-rc7 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xc1/0x5e0 mm/kasan/report.c:475
kasan_report+0xbe/0xf0 mm/kasan/report.c:588
strlen+0x7d/0xa0 lib/string.c:418
__fortify_strlen include/linux/fortify-string.h:210 [inline]
in4_pton+0xa3/0x3f0 net/core/utils.c:130
bond_option_arp_ip_targets_set+0xc2/0x910
drivers/net/bonding/bond_options.c:1201
__bond_opt_set+0x2a4/0x1030 drivers/net/bonding/bond_options.c:767
__bond_opt_set_notify+0x48/0x150 drivers/net/bonding/bond_options.c:792
bond_opt_tryset_rtnl+0xda/0x160 drivers/net/bonding/bond_options.c:817
bonding_sysfs_store_option+0xa1/0x120 drivers/net/bonding/bond_sysfs.c:156
dev_attr_store+0x54/0x80 drivers/base/core.c:2366
sysfs_kf_write+0x114/0x170 fs/sysfs/file.c:136
kernfs_fop_write_iter+0x337/0x500 fs/kernfs/file.c:334
call_write_iter include/linux/fs.h:2020 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x96a/0xd80 fs/read_write.c:584
ksys_write+0x122/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
---[ end trace ]---
Fix it by adding a check of string length before using it.
Fixes: f9de11a16594 ("bonding: add ip checks when store ip target")
Signed-off-by: Yue Sun <samsun1006219@xxxxxxxxx>
Signed-off-by: Simon Horman <horms@xxxxxxxxxx>
Acked-by: Jay Vosburgh <jay.vosburgh@xxxxxxxxxxxxx>
Reviewed-by: Hangbin Liu <liuhangbin@xxxxxxxxx>
Link: https://patch.msgid.link/20240702-bond-oob-v6-1-2dfdba195c19@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/bonding/bond_options.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index c9aa28eee191d..a818720ef0e49 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -1074,9 +1074,9 @@ static int bond_option_arp_ip_targets_set(struct bonding *bond,
__be32 target;
if (newval->string) {
- if (!in4_pton(newval->string+1, -1, (u8 *)&target, -1, NULL)) {
- netdev_err(bond->dev, "invalid ARP target %pI4 specified\n",
- &target);
+ if (strlen(newval->string) < 1 ||
+ !in4_pton(newval->string + 1, -1, (u8 *)&target, -1, NULL)) {
+ netdev_err(bond->dev, "invalid ARP target specified\n");
return ret;
}
if (newval->string[0] == '+')
--
2.43.0
