CVE-2022-49890 Information

Description

In the Linux kernel the following vulnerability has been resolved:

capabilities: fix potential memleak on error path from vfs_getxattr_alloc()

In cap_inode_getsecurity() we will use vfs_getxattr_alloc() to complete the memory allocation of tmpbuf if we have completed the memory allocation of tmpbuf but failed to call handler->get(…) there will be a memleak in below logic:

|– ret = (int)vfs_getxattr_alloc(mnt_userns …) | / ^^^ alloc for tmpbuf / |– value = krealloc(xattr_value error + 1 flags) | / ^^^ alloc memory / |– error = handler->get(handler …) | / error! / |– xattr_value = value | / xattr_value is &tmpbuf (memory leak!) /

So we will try to free(tmpbuf) after vfs_getxattr_alloc() fails to fix it.

[PM: subject line and backtrace tweaks]

Reference

https://git.kernel.org/stable/c/0c3e6288da650d1ec911a259c77bc2d88e498603 https://git.kernel.org/stable/c/2de8eec8afb75792440b8900a01d52b8f6742fd1 https://git.kernel.org/stable/c/6bb00eb21c0fbf18e5d3538c9ff0cf63fd0ace85 https://git.kernel.org/stable/c/7480aeff0093d8c54377553ec6b31110bea37b4d https://git.kernel.org/stable/c/8cf0a1bc12870d148ae830a4ba88cfdf0e879cee https://git.kernel.org/stable/c/90577bcc01c4188416a47269f8433f70502abe98 https://git.kernel.org/stable/c/cdf01c807e974048c43c7fd3ca574f6086a57906