seq_file: disallow extremely large seq buffer allocations

commit 8cae8cd89f05f6de223d63e6d15e31c8ba9cf53b upstream.

There is no reasonable need for a buffer larger than this, and it avoids
int overflow pitfalls.

Change-Id: I0ac12a4a1c51e476a9305e0c9d5247293b3083d4
Fixes: 058504edd0 ("fs/seq_file: fallback to vmalloc allocation")
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 6de9f0bf7c
Git-repo: https://android.googlesource.com/kernel/msm
Signed-off-by: PavanKumar S.R <quic_pavasr@quicinc.com>
This commit is contained in:
Eric Sandeen 2021-07-13 17:49:23 +02:00 committed by PavanKumar S.R
parent 2959ed5eb8
commit c91fec2811

View File

@ -29,6 +29,9 @@ static void seq_set_overflow(struct seq_file *m)
static void *seq_buf_alloc(unsigned long size)
{
if (unlikely(size > MAX_RW_COUNT))
return NULL;
return kvmalloc(size, GFP_KERNEL_ACCOUNT);
}