Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix double free in create_space_info() error path When kobject_init_and_add() fails, the call chain is: create_space_info() -> btrfs_sysfs_add_space_info_type() -> kobject_init_and_add() -> failure -> kobject_put(&space_info->kobj) -> space_info_release() -> kfree(space_info) Then control returns to create_space_info(): btrfs_sysfs_add_space_info_type() returns error -> goto out_free -> kfree(space_info) This causes a double free. Keep the direct kfree(space_info) for the earlier failure path, but after btrfs_sysfs_add_space_info_type() has called kobject_put(), let the kobject release callback handle the cleanup.

References 6

• git.kernel.org https://git.kernel.org/stable/c/3f487be81292702a59ea9dbc4088b3360a50e837
• git.kernel.org https://git.kernel.org/stable/c/9a060970fd7b5e1c561e4ce73cb9949e4269a738
• git.kernel.org https://git.kernel.org/stable/c/ae6d6e31ceb72b7697c28a528e4923c08e3c2ef5
• git.kernel.org https://git.kernel.org/stable/c/c2670ec4aa49ca226bce9776601e0da37502be07
• git.kernel.org https://git.kernel.org/stable/c/dd6ade0fdd59218d71a981ae7c937a304e49209c
• git.kernel.org https://git.kernel.org/stable/c/f414b3abbba59ef379a2b3c31f2bdd9358ed5e53

Remediation