From: Heiko Schocher Date: Thu, 21 Apr 2016 10:16:58 +0000 (+0200) Subject: ubifs: fix memory corruption in super.c X-Git-Tag: v2016.05-rc3~30^2 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=b1d6590d357bde2332cb699e2fd2efc7a7c64f38;p=oweals%2Fu-boot.git ubifs: fix memory corruption in super.c In list "super_blocks" ubifs collects allocated super_block structs. U-Boot frees on unmount the allocated struct, so the pointer stored in this list is free after the umount. On a new ubifs mount, the new allocated super_block struct get inserted into the super_blocks list ... which contains now a freed pointer, and the list_add_tail() corrupts the freed memory ... 2 solutions are possible: - remove the super_block from the super_blocks list on umount - as U-Boot does not use the super_blocks list ... remove it complete for U-Boot. Both solutions should not introduce problems for porting to newer linux version, so this patch removes the unused super_blocks list, as it saves code size and execution time. Signed-off-by: Heiko Schocher --- diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index dcf3a47947..effa8d933f 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -48,7 +48,6 @@ struct vfsmount; #define INODE_LOCKED_MAX 64 struct super_block *ubifs_sb; -LIST_HEAD(super_blocks); static struct inode *inodes_locked_down[INODE_LOCKED_MAX]; @@ -2425,10 +2424,10 @@ retry: s->s_type = type; #ifndef __UBOOT__ strlcpy(s->s_id, type->name, sizeof(s->s_id)); + list_add_tail(&s->s_list, &super_blocks); #else strncpy(s->s_id, type->name, sizeof(s->s_id)); #endif - list_add_tail(&s->s_list, &super_blocks); hlist_add_head(&s->s_instances, &type->fs_supers); #ifndef __UBOOT__ spin_unlock(&sb_lock);