This is a note to let you know that I've just added the patch titled
pipe: fix off-by-one error when checking buffer limits
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pipe-fix-off-by-one-error-when-checking-buffer-limits.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9903a91c763ecdae333a04a9d89d79d2b8966503 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Date: Tue, 6 Feb 2018 15:41:56 -0800
Subject: pipe: fix off-by-one error when checking buffer limits
From: Eric Biggers <ebiggers@xxxxxxxxxx>
commit 9903a91c763ecdae333a04a9d89d79d2b8966503 upstream.
With pipe-user-pages-hard set to 'N', users were actually only allowed up
to 'N - 1' buffers; and likewise for pipe-user-pages-soft.
Fix this to allow up to 'N' buffers, as would be expected.
Link: http://lkml.kernel.org/r/20180111052902.14409-5-ebiggers3@xxxxxxxxx
Fixes: b0b91d18e2e9 ("pipe: fix limit checking in pipe_set_size()")
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Acked-by: Willy Tarreau <w@xxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: "Luis R . Rodriguez" <mcgrof@xxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Cc: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/pipe.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -609,12 +609,12 @@ static unsigned long account_pipe_buffer
static bool too_many_pipe_buffers_soft(unsigned long user_bufs)
{
- return pipe_user_pages_soft && user_bufs >= pipe_user_pages_soft;
+ return pipe_user_pages_soft && user_bufs > pipe_user_pages_soft;
}
static bool too_many_pipe_buffers_hard(unsigned long user_bufs)
{
- return pipe_user_pages_hard && user_bufs >= pipe_user_pages_hard;
+ return pipe_user_pages_hard && user_bufs > pipe_user_pages_hard;
}
static bool is_unprivileged_user(void)
Patches currently in stable-queue which might be from ebiggers@xxxxxxxxxx are
queue-4.9/pipe-fix-off-by-one-error-when-checking-buffer-limits.patch
queue-4.9/crypto-cryptd-pass-through-absence-of-setkey.patch
queue-4.9/pipe-actually-allow-root-to-exceed-the-pipe-buffer-limits.patch
queue-4.9/kernel-relay.c-revert-kernel-relay.c-fix-potential-memory-leak.patch
queue-4.9/nfs-reject-request-for-id_legacy-key-without-auxdata.patch
queue-4.9/crypto-poly1305-remove-setkey-method.patch
queue-4.9/crypto-sha512-mb-initialize-pending-lengths-correctly.patch
queue-4.9/crypto-hash-introduce-crypto_hash_alg_has_setkey.patch
queue-4.9/crypto-mcryptd-pass-through-absence-of-setkey.patch