From: Peter Zijlstra <peterz@infradead.org>
syzbot used a negative node number which was not rejected early and led
to invalid memory access in node_possible().
Reject negative node numbers except for FUTEX_NO_NODE.
[bigeasy: Keep the FUTEX_NO_NODE check]
Reported-by: syzbot+9afaf6749e3a7aa1bdf3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6835bfe3.a70a0220.253bc2.00b5.GAE@google.com/
Fixes: cec199c5e39bd ("futex: Implement FUTEX2_NUMA")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/futex/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/futex/core.c b/kernel/futex/core.c
index 565f9717c6caa..b652d2f60c409 100644
--- a/kernel/futex/core.c
+++ b/kernel/futex/core.c
@@ -583,8 +583,8 @@ int get_futex_key(u32 __user *uaddr, unsigned int flags, union futex_key *key,
if (futex_get_value(&node, naddr))
return -EFAULT;
- if (node != FUTEX_NO_NODE &&
- (node >= MAX_NUMNODES || !node_possible(node)))
+ if ((node != FUTEX_NO_NODE) &&
+ ((unsigned int)node >= MAX_NUMNODES || !node_possible(node)))
return -EINVAL;
}
--
2.49.0