Messages in this thread Patch in this message | | | From | Jia-Ju Bai <> | Subject | [PATCH] isdn: mISDN: tei: Fix a sleep-in-atomic-context bug in create_teimgr() | Date | Sat, 1 Sep 2018 20:00:19 +0800 |
| |
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/tei.c, 1058: kzalloc 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 <baijiaju1990@gmail.com> --- drivers/isdn/mISDN/tei.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/isdn/mISDN/tei.c b/drivers/isdn/mISDN/tei.c index 12d9e5f4beb1..6d95ee639fdb 100644 --- a/drivers/isdn/mISDN/tei.c +++ b/drivers/isdn/mISDN/tei.c @@ -1055,7 +1055,7 @@ create_teimgr(struct manager *mgr, struct channel_req *crq) crq->adr.tei, crq->adr.sapi); if (!l2) return -ENOMEM; - l2->tm = kzalloc(sizeof(struct teimgr), GFP_KERNEL); + l2->tm = kzalloc(sizeof(struct teimgr), GFP_ATOMIC); if (!l2->tm) { kfree(l2); printk(KERN_ERR "kmalloc teimgr failed\n"); -- 2.17.0
| |