pidfs: validate extensible ioctls

[ Upstream commit 3c17001b21 ]

Validate extensible ioctls stricter than we do now.

Reviewed-by: Aleksa Sarai <cyphar@cyphar.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Christian Brauner
2025-09-12 13:52:24 +02:00
committed by Greg Kroah-Hartman
parent 9f0f659ea9
commit bf0fbf5e8b
2 changed files with 15 additions and 1 deletions

View File

@@ -440,7 +440,7 @@ static bool pidfs_ioctl_valid(unsigned int cmd)
* erronously mistook the file descriptor for a pidfd.
* This is not perfect but will catch most cases.
*/
return (_IOC_TYPE(cmd) == _IOC_TYPE(PIDFD_GET_INFO));
return extensible_ioctl_valid(cmd, PIDFD_GET_INFO, PIDFD_INFO_SIZE_VER0);
}
return false;

View File

@@ -4025,4 +4025,18 @@ static inline bool vfs_empty_path(int dfd, const char __user *path)
int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter);
static inline bool extensible_ioctl_valid(unsigned int cmd_a,
unsigned int cmd_b, size_t min_size)
{
if (_IOC_DIR(cmd_a) != _IOC_DIR(cmd_b))
return false;
if (_IOC_TYPE(cmd_a) != _IOC_TYPE(cmd_b))
return false;
if (_IOC_NR(cmd_a) != _IOC_NR(cmd_b))
return false;
if (_IOC_SIZE(cmd_a) < min_size)
return false;
return true;
}
#endif /* _LINUX_FS_H */