In the Linux kernel, the following vulnerability has been resolved: ext4: fix invalid free tracking in ext4_xattr_move_to_block() In ext4_xattr_move_to_block(), the value of the extended attribute which we need to move to an external block may be allocated by kvmalloc() if the value is stored in an external inode. So at the end of the function the code tried to check if this was the case by testing entry->e_value_inum. However, at this point, the pointer to the xattr entry is no longer valid, because it was removed from the original location where it had been stored. So we could end up calling kvfree() on a pointer which was not allocated by kvmalloc(); or we could also potentially leak memory by not freeing the buffer when it should be freed. Fix this by storing whether it should be freed in a separate variable.
https://git.kernel.org/stable/c/f30f3391d089dc91aef91d08f4b04a6c0df2b067
https://git.kernel.org/stable/c/c5fa4eedddd1c8342ce533cb401c0e693e55b4e3
https://git.kernel.org/stable/c/ba04d6af5ac440a6d5a2d35dc1d8e2cb0323550a
https://git.kernel.org/stable/c/b87c7cdf2bed4928b899e1ce91ef0d147017ba45
https://git.kernel.org/stable/c/b2fab1807d26acd1c6115b95b5eddd697d84751b
https://git.kernel.org/stable/c/a18670395e5f28acddeca037c5e4bd2ea961b70a
https://git.kernel.org/stable/c/8beaa3cb293a8f7bacf711cf52201d59859dbc40
https://git.kernel.org/stable/c/76887be2a96193cd11be818551b8934ecdb3123f
https://git.kernel.org/stable/c/1a8822343e67432b658145d2760a524c884da9d4