The kernel module may sleep with holding a spinlock.
The function call paths (from bottom to top) in Linux-4.16 are:
[FUNC] kzalloc(GFP_KERNEL)
drivers/isdn/mISDN/layer2.c, 2126: kzalloc in create_l2
drivers/isdn/mISDN/tei.c, 1054: create_l2 in create_teimgr
drivers/isdn/mISDN/tei.c, 1278: create_teimgr in mgr_ctrl
drivers/isdn/mISDN/tei.c, 1048: [FUNC_PTR]mgr_ctrl in create_teimgr
drivers/isdn/mISDN/tei.c, 1045: _raw_read_lock_irqsave in create_teimgr
Note that [FUNC_PTR] means a function pointer call is used.
To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC.
This bug is found by my static analysis tool DSAC
Signed-off-by: Jia-Ju Bai <[email protected]>
---
drivers/isdn/mISDN/layer2.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/isdn/mISDN/layer2.c b/drivers/isdn/mISDN/layer2.c
index 9ff0903a0e89..383f31ae4b92 100644
--- a/drivers/isdn/mISDN/layer2.c
+++ b/drivers/isdn/mISDN/layer2.c
@@ -2123,7 +2123,7 @@ create_l2(struct mISDNchannel *ch, u_int protocol, u_long options, int tei,
struct layer2 *l2;
struct channel_req rq;
- l2 = kzalloc(sizeof(struct layer2), GFP_KERNEL);
+ l2 = kzalloc(sizeof(struct layer2), GFP_ATOMIC);
if (!l2) {
printk(KERN_ERR "kzalloc layer2 failed\n");
return NULL;
--
2.17.0