The interface for fcntl expects the argument passed for the command F_ADD_SEALS to be of type int. The current code wrongly treats it as a long. In order to avoid access to undefined bits, we should explicitly cast the argument to int.
This commit changes the signature of all the related and helper functions so that they treat the argument as int instead of long.
Cc: Andrew Morton akpm@linux-foundation.org Cc: Alexander Viro viro@zeniv.linux.org.uk Cc: Christian Brauner brauner@kernel.org Cc: Jeff Layton jlayton@kernel.org Cc: Chuck Lever chuck.lever@oracle.com Cc: Kevin Brodsky Kevin.Brodsky@arm.com Cc: Vincenzo Frascino Vincenzo.Frascino@arm.com Cc: Szabolcs Nagy Szabolcs.Nagy@arm.com Cc: "Theodore Ts'o" tytso@mit.edu Cc: David Laight David.Laight@ACULAB.com Cc: Mark Rutland Mark.Rutland@arm.com Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-morello@op-lists.linaro.org Signed-off-by: Luca Vizzarro Luca.Vizzarro@arm.com --- include/linux/memfd.h | 4 ++-- mm/memfd.c | 6 +----- 2 files changed, 3 insertions(+), 7 deletions(-)
diff --git a/include/linux/memfd.h b/include/linux/memfd.h index 4f1600413f91..e7abf6fa4c52 100644 --- a/include/linux/memfd.h +++ b/include/linux/memfd.h @@ -5,9 +5,9 @@ #include <linux/file.h>
#ifdef CONFIG_MEMFD_CREATE -extern long memfd_fcntl(struct file *file, unsigned int cmd, unsigned long arg); +extern long memfd_fcntl(struct file *file, unsigned int cmd, unsigned int arg); #else -static inline long memfd_fcntl(struct file *f, unsigned int c, unsigned long a) +static inline long memfd_fcntl(struct file *f, unsigned int c, unsigned int a) { return -EINVAL; } diff --git a/mm/memfd.c b/mm/memfd.c index a0a7a37e8177..69b90c31d38c 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -243,16 +243,12 @@ static int memfd_get_seals(struct file *file) return seals ? *seals : -EINVAL; }
-long memfd_fcntl(struct file *file, unsigned int cmd, unsigned long arg) +long memfd_fcntl(struct file *file, unsigned int cmd, unsigned int arg) { long error;
switch (cmd) { case F_ADD_SEALS: - /* disallow upper 32bit */ - if (arg > UINT_MAX) - return -EINVAL; - error = memfd_add_seals(file, arg); break; case F_GET_SEALS: