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authorNikolay Borisov <kernel@kyup.com>2016-06-29 09:46:41 +0300
committerDavid Sterba <dsterba@suse.com>2016-07-26 13:52:25 +0200
commit3d48d9810de4ee1bca4a1c905efd0618944904cd (patch)
tree1bdd8f5dd630aa97d03bd17cda4049d84335eebc
parentfb770ae414d018255afa7a70b14ba1f8620762dd (diff)
downloadlinux-3d48d9810de4ee1bca4a1c905efd0618944904cd.tar.bz2
btrfs: Handle uninitialised inode eviction
The code flow in btrfs_new_inode allows for btrfs_evict_inode to be called with not fully initialised inode (e.g. ->root member not being set). This can happen when btrfs_set_inode_index in btrfs_new_inode fails, which in turn would call iput for the newly allocated inode. This in turn leads to vfs calling into btrfs_evict_inode. This leads to null pointer dereference. To handle this situation check whether the passed inode has root set and just free it in case it doesn't. Signed-off-by: Nikolay Borisov <kernel@kyup.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
-rw-r--r--fs/btrfs/inode.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3e61bd1f3f65..5c2c076bc552 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5159,11 +5159,18 @@ void btrfs_evict_inode(struct inode *inode)
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv, *global_rsv;
int steal_from_global = 0;
- u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
+ u64 min_size;
int ret;
trace_btrfs_inode_evict(inode);
+ if (!root) {
+ kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+ return;
+ }
+
+ min_size = btrfs_calc_trunc_metadata_size(root, 1);
+
evict_inode_truncate_pages(inode);
if (inode->i_nlink &&