Messages in this thread Patch in this message | | | From | Norbert Manthey <> | Subject | [PATCH pstore fix v1] pstore: fix use after free | Date | Fri, 5 Jul 2019 15:06:00 +0200 |
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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>
--- fs/pstore/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -333,7 +333,6 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record) private = kzalloc(sizeof(*private), GFP_KERNEL); if (!private) goto fail_alloc; - private->record = record; switch (record->type) { case PSTORE_TYPE_DMESG: @@ -387,6 +386,8 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record) if (!dentry) goto fail_private; + private->record = record; + inode->i_size = private->total_size = size; inode->i_private = private; -- 2.7.4
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