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authorNorbert Manthey <nmanthey@amazon.de>2019-07-05 15:06:00 +0200
committerKees Cook <keescook@chromium.org>2019-07-09 06:04:42 +0200
commit4c6d80e1144bdf48cae6b602ae30d41f3e5c76a9 (patch)
tree5bfffd85fa86428abcd5d529f5f38f79a0c43dfd
parentpstore: no need to check return value of debugfs_create functions (diff)
downloadlinux-4c6d80e1144bdf48cae6b602ae30d41f3e5c76a9.tar.xz
linux-4c6d80e1144bdf48cae6b602ae30d41f3e5c76a9.zip
pstore: Fix double-free in pstore_mkfile() failure path
The pstore_mkfile() function is passed a pointer to a struct pstore_record. On success it consumes this 'record' pointer and references it from the created inode. On failure, however, it may or may not free the record. There are even two different code paths which return -ENOMEM -- one of which does and the other doesn't free the record. Make the behaviour deterministic by never consuming and freeing the record when returning failure, allowing the caller to do the cleanup consistently. Signed-off-by: Norbert Manthey <nmanthey@amazon.de> Link: https://lore.kernel.org/r/1562331960-26198-1-git-send-email-nmanthey@amazon.de Fixes: 83f70f0769ddd ("pstore: Do not duplicate record metadata") Fixes: 1dfff7dd67d1a ("pstore: Pass record contents instead of copying") Cc: stable@vger.kernel.org [kees: also move "private" allocation location, rename inode cleanup label] Signed-off-by: Kees Cook <keescook@chromium.org>
-rw-r--r--fs/pstore/inode.c13
1 files changed, 6 insertions, 7 deletions
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 89a80b568a17..7fbe8f058220 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -318,22 +318,21 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
goto fail;
inode->i_mode = S_IFREG | 0444;
inode->i_fop = &pstore_file_operations;
- private = kzalloc(sizeof(*private), GFP_KERNEL);
- if (!private)
- goto fail_alloc;
- private->record = record;
-
scnprintf(name, sizeof(name), "%s-%s-%llu%s",
pstore_type_to_name(record->type),
record->psi->name, record->id,
record->compressed ? ".enc.z" : "");
+ private = kzalloc(sizeof(*private), GFP_KERNEL);
+ if (!private)
+ goto fail_inode;
+
dentry = d_alloc_name(root, name);
if (!dentry)
goto fail_private;
+ private->record = record;
inode->i_size = private->total_size = size;
-
inode->i_private = private;
if (record->time.tv_sec)
@@ -349,7 +348,7 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
fail_private:
free_pstore_private(private);
-fail_alloc:
+fail_inode:
iput(inode);
fail: