[PATCH 1/2] xfs: check the return value of krealloc()

[Zhen Lei]

krealloc() may fail to expand the memory space. Add sanity checks to it,
and WARN() if that really happened.

Signed-off-by: Zhen Lei <thunder.leiz...@huawei.com>
---
 fs/xfs/libxfs/xfs_inode_fork.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
index 7575de5cecb1..4e457aea8493 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c
@@ -366,6 +366,8 @@ xfs_iroot_realloc(
 
        ifp = XFS_IFORK_PTR(ip, whichfork);
        if (rec_diff > 0) {
+               struct xfs_btree_block *if_broot;
+
                /*
                 * If there wasn't any memory allocated before, just
                 * allocate it now and get out.
@@ -386,8 +388,13 @@ xfs_iroot_realloc(
                cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
                new_max = cur_max + rec_diff;
                new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
-               ifp->if_broot = krealloc(ifp->if_broot, new_size,
-                                        GFP_NOFS | __GFP_NOFAIL);
+               if_broot = krealloc(ifp->if_broot, new_size,
+                                   GFP_NOFS | __GFP_NOFAIL);
+               if (!if_broot) {
+                       WARN(1, "if_broot realloc failed\n");
+                       return;
+               }
+               ifp->if_broot = if_broot;
                op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
                                                     ifp->if_broot_bytes);
                np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
@@ -477,6 +484,7 @@ xfs_idata_realloc(
 {
        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
        int64_t                 new_size = ifp->if_bytes + byte_diff;
+       char *if_data;
 
        ASSERT(new_size >= 0);
        ASSERT(new_size <= XFS_IFORK_SIZE(ip, whichfork));
@@ -496,8 +504,13 @@ xfs_idata_realloc(
         * in size so that it can be logged and stay on word boundaries.
         * We enforce that here.
         */
-       ifp->if_u1.if_data = krealloc(ifp->if_u1.if_data, roundup(new_size, 4),
+       if_data = krealloc(ifp->if_u1.if_data, roundup(new_size, 4),
                                      GFP_NOFS | __GFP_NOFAIL);
+       if (!if_data) {
+               WARN(1, "if_data realloc failed\n");
+               return;
+       }
+       ifp->if_u1.if_data = if_data;
        ifp->if_bytes = new_size;
 }
 
-- 
2.26.0.106.g9fadedd