queue-4.19/f2fs-fix-to-adapt-small-inline-xattr-space-in-__find.patch

   1 From 0d596546dffb95665dd98256ec05eefb91bd2f51 Mon Sep 17 00:00:00 2001
   2 From: Chao Yu <yuchao0@huawei.com>
   3 Date: Tue, 5 Mar 2019 19:32:26 +0800
   4 Subject: f2fs: fix to adapt small inline xattr space in __find_inline_xattr()
   5
   6 [ Upstream commit 2c28aba8b2e2a51749fa66e01b68e1cd5b53e022 ]
   7
   8 With below testcase, we will fail to find existed xattr entry:
   9
  10 1. mkfs.f2fs -O extra_attr -O flexible_inline_xattr /dev/zram0
  11 2. mount -t f2fs -o inline_xattr_size=1 /dev/zram0 /mnt/f2fs/
  12 3. touch /mnt/f2fs/file
  13 4. setfattr -n "user.name" -v 0 /mnt/f2fs/file
  14 5. getfattr -n "user.name" /mnt/f2fs/file
  15
  16 /mnt/f2fs/file: user.name: No such attribute
  17
  18 The reason is for inode which has very small inline xattr size,
  19 __find_inline_xattr() will fail to traverse any entry due to first
  20 entry may not be loaded from xattr node yet, later, we may skip to
  21 check entire xattr datas in __find_xattr(), result in such wrong
  22 condition.
  23
  24 This patch adds condition to check such case to avoid this issue.
  25
  26 Signed-off-by: Chao Yu <yuchao0@huawei.com>
  27 Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
  28 Signed-off-by: Sasha Levin <sashal@kernel.org>
  29 ---
  30  fs/f2fs/xattr.c | 13 ++++++++++---
  31  1 file changed, 10 insertions(+), 3 deletions(-)
  32
  33 diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
  34 index 087e53a2d96c..409a637f7a92 100644
  35 --- a/fs/f2fs/xattr.c
  36 +++ b/fs/f2fs/xattr.c
  37 @@ -227,11 +227,11 @@ static struct f2fs_xattr_entry *__find_inline_xattr(struct inode *inode,
  38  {
  39         struct f2fs_xattr_entry *entry;
  40         unsigned int inline_size = inline_xattr_size(inode);
  41 +       void *max_addr = base_addr + inline_size;
  42
  43         list_for_each_xattr(entry, base_addr) {
  44 -               if ((void *)entry + sizeof(__u32) > base_addr + inline_size ||
  45 -                       (void *)XATTR_NEXT_ENTRY(entry) + sizeof(__u32) >
  46 -                       base_addr + inline_size) {
  47 +               if ((void *)entry + sizeof(__u32) > max_addr ||
  48 +                       (void *)XATTR_NEXT_ENTRY(entry) > max_addr) {
  49                         *last_addr = entry;
  50                         return NULL;
  51                 }
  52 @@ -242,6 +242,13 @@ static struct f2fs_xattr_entry *__find_inline_xattr(struct inode *inode,
  53                 if (!memcmp(entry->e_name, name, len))
  54                         break;
  55         }
  56 +
  57 +       /* inline xattr header or entry across max inline xattr size */
  58 +       if (IS_XATTR_LAST_ENTRY(entry) &&
  59 +               (void *)entry + sizeof(__u32) > max_addr) {
  60 +               *last_addr = entry;
  61 +               return NULL;
  62 +       }
  63         return entry;
  64  }
  65
  66 --
  67 2.19.1
  68