Messages in this thread Patch in this message | | | From | Jia-Ju Bai <> | Subject | [PATCH] block/drbd: Fix a sleep-in-atomic bug in notify_helper | Date | Wed, 4 Oct 2017 09:37:29 +0800 |
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The driver may sleep under a RCU lock, and the function call path is: drbd_sync_handshake (acquire the RCU lock) drbd_asb_recover_1p drbd_khelper notify_helper genlmsg_new(GFP_NOIO) --> may sleep
To fix it, GFP_NOIO is replaced with GFP_ATOMIC. This bug is found by my static analysis tool and my code review.
Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com> --- drivers/block/drbd/drbd_nl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index a12f77e..ad093da 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -4790,7 +4790,7 @@ void notify_helper(enum drbd_notification_type type, helper_info.helper_name_len = min(strlen(name), sizeof(helper_info.helper_name)); helper_info.helper_status = status; - skb = genlmsg_new(NLMSG_GOODSIZE, GFP_NOIO); + skb = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); err = -ENOMEM; if (!skb) goto fail; -- 1.7.9.5
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