]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
usercopy: Make usercopy resilient against ridiculously large copies
authorMatthew Wilcox (Oracle) <willy@infradead.org>
Sun, 12 Jun 2022 21:32:27 +0000 (22:32 +0100)
committerKees Cook <keescook@chromium.org>
Mon, 13 Jun 2022 16:54:52 +0000 (09:54 -0700)
commit1dfbe9fcda4afc957f0e371e207ae3cb7e8f3b0e
tree5d113acb38d1b7af478d04036fc46d55134c578b
parent35fb9ae4aa2e838b234323e6f7cf6336ff019e5a
usercopy: Make usercopy resilient against ridiculously large copies

If 'n' is so large that it's negative, we might wrap around and mistakenly
think that the copy is OK when it's not.  Such a copy would probably
crash, but just doing the arithmetic in a more simple way lets us detect
and refuse this case.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Tested-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220612213227.3881769-4-willy@infradead.org
mm/usercopy.c