Re: [syzbot] possible deadlock in input_event (2)

From: Jeongjun Park
Date: Fri Apr 19 2024 - 12:34:00 EST



please test deadlock in input_event

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

---
fs/fcntl.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 54cc85d3338e..30f4d75fdb03 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -829,7 +829,7 @@ int send_sigurg(struct fown_struct *fown)
struct task_struct *p;
enum pid_type type;
struct pid *pid;
- unsigned long flags;
+ unsigned long flags, read_flags;
int ret = 0;

read_lock_irqsave(&fown->lock, flags);
@@ -848,11 +848,11 @@ int send_sigurg(struct fown_struct *fown)
send_sigurg_to_task(p, fown, type);
rcu_read_unlock();
} else {
- read_lock(&tasklist_lock);
+ read_lock_irqsave(&tasklist_lock, read_flags);
do_each_pid_task(pid, type, p) {
send_sigurg_to_task(p, fown, type);
} while_each_pid_task(pid, type, p);
- read_unlock(&tasklist_lock);
+ read_unlock_irqrestore(&tasklist_lock, read_flags);
}
out_unlock_fown:
read_unlock_irqrestore(&fown->lock, flags);
--
2.34.1