5.4-stable review patch. If anyone has any objections, please let me know.
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From: Ferry Meng mengferry@linux.alibaba.com
[ Upstream commit 9e3041fecdc8f78a5900c3aa51d3d756e73264d6 ]
Add a paranoia check to make sure it doesn't stray beyond valid memory region containing ocfs2 xattr entries when scanning for a match. It will prevent out-of-bound access in case of crafted images.
Link: https://lkml.kernel.org/r/20240520024024.1976129-1-joseph.qi@linux.alibaba.c... Signed-off-by: Ferry Meng mengferry@linux.alibaba.com Signed-off-by: Joseph Qi joseph.qi@linux.alibaba.com Reported-by: lei lu llfamsec@gmail.com Reviewed-by: Joseph Qi joseph.qi@linux.alibaba.com Cc: Mark Fasheh mark@fasheh.com Cc: Joel Becker jlbec@evilplan.org Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Changwei Ge gechangwei@live.cn Cc: Gang He ghe@suse.com Cc: Jun Piao piaojun@huawei.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Stable-dep-of: af77c4fc1871 ("ocfs2: strict bound check before memcmp in ocfs2_xattr_find_entry()") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ocfs2/xattr.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index 9ccd19d8f7b18..16bf7bb8f0db0 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -1068,7 +1068,7 @@ ssize_t ocfs2_listxattr(struct dentry *dentry, return i_ret + b_ret; }
-static int ocfs2_xattr_find_entry(int name_index, +static int ocfs2_xattr_find_entry(struct inode *inode, int name_index, const char *name, struct ocfs2_xattr_search *xs) { @@ -1082,6 +1082,10 @@ static int ocfs2_xattr_find_entry(int name_index, name_len = strlen(name); entry = xs->here; for (i = 0; i < le16_to_cpu(xs->header->xh_count); i++) { + if ((void *)entry >= xs->end) { + ocfs2_error(inode->i_sb, "corrupted xattr entries"); + return -EFSCORRUPTED; + } cmp = name_index - ocfs2_xattr_get_type(entry); if (!cmp) cmp = name_len - entry->xe_name_len; @@ -1172,7 +1176,7 @@ static int ocfs2_xattr_ibody_get(struct inode *inode, xs->base = (void *)xs->header; xs->here = xs->header->xh_entries;
- ret = ocfs2_xattr_find_entry(name_index, name, xs); + ret = ocfs2_xattr_find_entry(inode, name_index, name, xs); if (ret) return ret; size = le64_to_cpu(xs->here->xe_value_size); @@ -2704,7 +2708,7 @@ static int ocfs2_xattr_ibody_find(struct inode *inode,
/* Find the named attribute. */ if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) { - ret = ocfs2_xattr_find_entry(name_index, name, xs); + ret = ocfs2_xattr_find_entry(inode, name_index, name, xs); if (ret && ret != -ENODATA) return ret; xs->not_found = ret; @@ -2839,7 +2843,7 @@ static int ocfs2_xattr_block_find(struct inode *inode, xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size; xs->here = xs->header->xh_entries;
- ret = ocfs2_xattr_find_entry(name_index, name, xs); + ret = ocfs2_xattr_find_entry(inode, name_index, name, xs); } else ret = ocfs2_xattr_index_block_find(inode, blk_bh, name_index,