tree b601aedbf469e820810940d317e134692565555b
parent 4d9c35b65ed4e79e7f9fc51230cd7be45a3c9826
author Linus Torvalds <torvalds@linux-foundation.org> 1670268820 -0800
committer COS Cherry Picker <cloud-image-release@prod.google.com> 1670958374 -0800

proc: avoid integer type confusion in get_proc_long

commit e6cfaf34be9fcd1a8285a294e18986bfc41a409c upstream.

proc_get_long() is passed a size_t, but then assigns it to an 'int'
variable for the length.  Let's not do that, even if our IO paths are
limited to MAX_RW_COUNT (exactly because of these kinds of type errors).

So do the proper test in the right type.

BUG=b/261741918
TEST=presubmit
SOURCE=UPSTREAM e6cfaf34be9fcd1a8285a294e18986bfc41a409c
RELEASE_NOTE=Fixed a type error in proc_get_long. This resolves
CVE-2022-4378.

cos-patch: security-moderate
Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Change-Id: Icf3fbedf0d4a698b2a3e0607c6fdfadb14639beb
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/40009
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
Main-Branch-Verified: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>