[PATCH 6.6 03/16] jfs: dont walk off the end of ealist

Greg Kroah-Hartman
2024-07-25T14:45:56Z

From: lei lu <llfamsec@gmail.com>

commit d0fa70aca54c8643248e89061da23752506ec0d4 upstream.

Add a check before visiting the members of ea to
make sure each ea stays within the ealist.

Signed-off-by: lei lu <llfamsec@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/jfs/xattr.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)

--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -797,7 +797,7 @@ ssize_t __jfs_getxattr(struct inode *ino
size_t buf_size)
{
struct jfs_ea_list *ealist;
- struct jfs_ea *ea;
+ struct jfs_ea *ea, *ealist_end;
struct ea_buffer ea_buf;
int xattr_size;
ssize_t size;
@@ -817,9 +817,16 @@ ssize_t __jfs_getxattr(struct inode *ino
goto not_found;

ealist = (struct jfs_ea_list *) ea_buf.xattr;
+ ealist_end = END_EALIST(ealist);

/* Find the named attribute */
- for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
+ for (ea = FIRST_EA(ealist); ea < ealist_end; ea = NEXT_EA(ea)) {
+ if (unlikely(ea + 1 > ealist_end) ||
+ unlikely(NEXT_EA(ea) > ealist_end)) {
+ size = -EUCLEAN;
+ goto release;
+ }
+
if ((namelen == ea->namelen) &&
memcmp(name, ea->name, namelen) == 0) {
/* Found it */
@@ -834,6 +841,7 @@ ssize_t __jfs_getxattr(struct inode *ino
memcpy(data, value, size);
goto release;
}
+ }
not_found:
size = -ENODATA;
release:
@@ -861,7 +869,7 @@ ssize_t jfs_listxattr(struct dentry * de
ssize_t size = 0;
int xattr_size;
struct jfs_ea_list *ealist;
- struct jfs_ea *ea;
+ struct jfs_ea *ea, *ealist_end;
struct ea_buffer ea_buf;

down_read(&JFS_IP(inode)->xattr_sem);
@@ -876,9 +884,16 @@ ssize_t jfs_listxattr(struct dentry * de
goto release;

ealist = (struct jfs_ea_list *) ea_buf.xattr;
+ ealist_end = END_EALIST(ealist);

/* compute required size of list */
- for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
+ for (ea = FIRST_EA(ealist); ea < ealist_end; ea = NEXT_EA(ea)) {
+ if (unlikely(ea + 1 > ealist_end) ||
+ unlikely(NEXT_EA(ea) > ealist_end)) {
+ size = -EUCLEAN;
+ goto release;
+ }
+
if (can_list(ea))
size += name_size(ea) + 1;
}