Btrfs: avoid buffer overrun in btrfs_printk
The buffer read-overrun would be triggered by a printk format
starting with <N>, where N is a single digit. NUL-terminate
after strncpy. Use memcpy, not strncpy, since we know the
string we're copying fits in the destination buffer and
contains no NUL byte.
Signed-off-by: Jim Meyering <meyering@redhat.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 2cd3217..46b2665 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -188,7 +188,8 @@
va_start(args, fmt);
if (fmt[0] == '<' && isdigit(fmt[1]) && fmt[2] == '>') {
- strncpy(lvl, fmt, 3);
+ memcpy(lvl, fmt, 3);
+ lvl[3] = '\0';
fmt += 3;
type = logtypes[fmt[1] - '0'];
} else