From: Jason A. Donenfeld Jason@zx2c4.com
commit 067baa9a37b32b95fdeabccde4b0cb6a2cf95f96 upstream.
By not checking whether llseek is NULL, this might jump to NULL. Also, it doesn't check FMODE_LSEEK. Fix this by using vfs_llseek(), which always does the right thing.
Fixes: f44158485826 ("cifsd: add file operations") Cc: stable@vger.kernel.org Cc: linux-cifs@vger.kernel.org Cc: Ronnie Sahlberg lsahlber@redhat.com Cc: Hyunchul Lee hyc.lee@gmail.com Cc: Sergey Senozhatsky sergey.senozhatsky@gmail.com Reviewed-by: Namjae Jeon linkinjeon@kernel.org Acked-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ksmbd/vfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/ksmbd/vfs.c +++ b/fs/ksmbd/vfs.c @@ -1051,7 +1051,7 @@ int ksmbd_vfs_fqar_lseek(struct ksmbd_fi *out_count = 0; end = start + length; while (start < end && *out_count < in_count) { - extent_start = f->f_op->llseek(f, start, SEEK_DATA); + extent_start = vfs_llseek(f, start, SEEK_DATA); if (extent_start < 0) { if (extent_start != -ENXIO) ret = (int)extent_start; @@ -1061,7 +1061,7 @@ int ksmbd_vfs_fqar_lseek(struct ksmbd_fi if (extent_start >= end) break;
- extent_end = f->f_op->llseek(f, extent_start, SEEK_HOLE); + extent_end = vfs_llseek(f, extent_start, SEEK_HOLE); if (extent_end < 0) { if (extent_end != -ENXIO) ret = (int)extent_end;