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authorEric Biggers <ebiggers@google.com>2018-02-06 15:41:56 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-17 13:21:18 +0100
commit71baf27d8c2b3db340e07412756093474be90883 (patch)
treeb7221591d5e080bbfe02bae8337566b3e34deda9
parenta705c24b5d5012be1165f0bc43997babd9ed2614 (diff)
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pipe: fix off-by-one error when checking buffer limits
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@gmail.com Fixes: b0b91d18e2e9 ("pipe: fix limit checking in pipe_set_size()") Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Willy Tarreau <w@1wt.eu> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/pipe.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/pipe.c b/fs/pipe.c
index 54e803f89743..34345535f63d 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -609,12 +609,12 @@ static unsigned long account_pipe_buffers(struct user_struct *user,
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)