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authorYueHaibing <yuehaibing@huawei.com>2023-07-15 17:25:43 +0800
committerMarc Kleine-Budde <mkl@pengutronix.de>2023-07-17 09:46:26 +0200
commit55c3b96074f3f9b0aee19bf93cd71af7516582bb (patch)
treee9a1cecd0f980f79e85d0754ed3925268f780209 /net/can
parentee8b94c8510ce64afe0b87ef548d23e00915fb10 (diff)
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can: bcm: Fix UAF in bcm_proc_show()
BUG: KASAN: slab-use-after-free in bcm_proc_show+0x969/0xa80 Read of size 8 at addr ffff888155846230 by task cat/7862 CPU: 1 PID: 7862 Comm: cat Not tainted 6.5.0-rc1-00153-gc8746099c197 #230 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0xd5/0x150 print_report+0xc1/0x5e0 kasan_report+0xba/0xf0 bcm_proc_show+0x969/0xa80 seq_read_iter+0x4f6/0x1260 seq_read+0x165/0x210 proc_reg_read+0x227/0x300 vfs_read+0x1d5/0x8d0 ksys_read+0x11e/0x240 do_syscall_64+0x35/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd Allocated by task 7846: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x9e/0xa0 bcm_sendmsg+0x264b/0x44e0 sock_sendmsg+0xda/0x180 ____sys_sendmsg+0x735/0x920 ___sys_sendmsg+0x11d/0x1b0 __sys_sendmsg+0xfa/0x1d0 do_syscall_64+0x35/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 7846: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x27/0x40 ____kasan_slab_free+0x161/0x1c0 slab_free_freelist_hook+0x119/0x220 __kmem_cache_free+0xb4/0x2e0 rcu_core+0x809/0x1bd0 bcm_op is freed before procfs entry be removed in bcm_release(), this lead to bcm_proc_show() may read the freed bcm_op. Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Oliver Hartkopp <socketcan@hartkopp.net> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/all/20230715092543.15548-1-yuehaibing@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/bcm.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 9ba35685b043..9168114fc87f 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -1526,6 +1526,12 @@ static int bcm_release(struct socket *sock)
lock_sock(sk);
+#if IS_ENABLED(CONFIG_PROC_FS)
+ /* remove procfs entry */
+ if (net->can.bcmproc_dir && bo->bcm_proc_read)
+ remove_proc_entry(bo->procname, net->can.bcmproc_dir);
+#endif /* CONFIG_PROC_FS */
+
list_for_each_entry_safe(op, next, &bo->tx_ops, list)
bcm_remove_op(op);
@@ -1561,12 +1567,6 @@ static int bcm_release(struct socket *sock)
list_for_each_entry_safe(op, next, &bo->rx_ops, list)
bcm_remove_op(op);
-#if IS_ENABLED(CONFIG_PROC_FS)
- /* remove procfs entry */
- if (net->can.bcmproc_dir && bo->bcm_proc_read)
- remove_proc_entry(bo->procname, net->can.bcmproc_dir);
-#endif /* CONFIG_PROC_FS */
-
/* remove device reference */
if (bo->bound) {
bo->bound = 0;