In the Linux kernel, the following vulnerability has been resolved:
dm era: fix NULL pointer dereference in metadata_open()
metadata_open() returns NULL when kzalloc_obj() fails, but the caller era_ctr() only checks IS_ERR(md). Since IS_ERR(NULL) returns false, the NULL pointer is treated as a valid result and later assigned to era->md, leading to a NULL pointer dereference when the metadata is accessed.
Fix this by returning ERR_PTR(-ENOMEM) on allocation failure, consistent with dm-cache-metadata.c, dm-thin-metadata.c, and dm-clone-metadata.c which all use ERR_PTR(-ENOMEM) for the same pattern.
References
- https://git.kernel.org/stable/c/01c49eae7c6256f2d8cc08210a2bac3ee070e43a
- https://git.kernel.org/stable/c/14e03ecd3b1b5fc03c082b27a2f8889f8290c30e
- https://git.kernel.org/stable/c/17eb2ab13edd0b06ce6f996c5fd450d7efabb2e8
- https://git.kernel.org/stable/c/889374b8e4a60d13fe4a5a8ae3a311ca93d1a2c3
- https://git.kernel.org/stable/c/9ae672606c17891d90b282e3490b817620549599
- https://git.kernel.org/stable/c/a705e056c2f3dd067fb2ff414f0537530baa090b
- https://git.kernel.org/stable/c/b69ea153d30ce19ca8997eeeca1e2219fae5a29b
- https://git.kernel.org/stable/c/bd5a80128bdfc93b1cae935a70da000b8c483e6e