use use SEEK_MAX to validate user lseek arguments
Add SEEK_MAX and use it to validate lseek arguments from userspace.
Signed-off-by: Chris Snook <csnook@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/read_write.c b/fs/read_write.c
index 0642a16..4d03008 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -139,7 +139,7 @@
goto bad;
retval = -EINVAL;
- if (origin <= 2) {
+ if (origin <= SEEK_MAX) {
loff_t res = vfs_llseek(file, offset, origin);
retval = res;
if (res != (loff_t)retval)
@@ -166,7 +166,7 @@
goto bad;
retval = -EINVAL;
- if (origin > 2)
+ if (origin > SEEK_MAX)
goto out_putf;
offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 020a842..986b5d5d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -30,6 +30,7 @@
#define SEEK_SET 0 /* seek relative to beginning of file */
#define SEEK_CUR 1 /* seek relative to current file position */
#define SEEK_END 2 /* seek relative to end of file */
+#define SEEK_MAX SEEK_END
/* And dynamically-tunable limits and defaults: */
struct files_stat_struct {