Commit ee767463 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

netdevsim: prevent bad user input in nsim_dev_health_break_write() 



If either a zero count or a large one is provided, kernel can crash.

Fixes: 82c93a87 ("netdevsim: implement couple of testing devlink health reporters")
Reported-by: default avatar <syzbot+ea40e4294e58b0292f74@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/netdev/675c6862.050a0220.37aaf.00b1.GAE@google.com/T/#u


Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: default avatarJoe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/20241213172518.2415666-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 2d5df3a6

drivers/net/netdevsim/health.c

+2 −0
Original line number Diff line number Diff line
@@ -149,6 +149,8 @@ static ssize_t nsim_dev_health_break_write(struct file *file, 
	char *break_msg;

	int err;



	if (count == 0 || count > PAGE_SIZE)

		return -EINVAL;

	break_msg = memdup_user_nul(data, count);

	if (IS_ERR(break_msg))

		return PTR_ERR(break_msg);