| From | Richard Weinberger <> | Date | Sun, 1 Jul 2018 20:48:07 +0200 | Subject | Re: [PATCH 4.17 154/220] UBIFS: Fix potential integer overflow in allocation |
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On Sun, Jul 1, 2018 at 6:22 PM, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > 4.17-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Silvio Cesare <silvio.cesare@gmail.com> > > commit 353748a359f1821ee934afc579cf04572406b420 upstream. > > There is potential for the size and len fields in ubifs_data_node to be > too large causing either a negative value for the length fields or an > integer overflow leading to an incorrect memory allocation. Likewise, > when the len field is small, an integer underflow may occur. > > Signed-off-by: Silvio Cesare <silvio.cesare@gmail.com> > Fixes: 1e51764a3c2ac ("UBIFS: add new flash file system") > Cc: stable@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Guys, this patch was never on linux-mtd nor was I CC'ed. I don't see it so super security critical which argues to bypass the whole community review process.
Anyway, I don't like this patch for two reasons. 1. Instead of doing the kmalloc_array() dance, just check whether size is 0 > and <= UBIFS_BLOCK_SIZE, in the caller. 2. It will not apply to most stable kernels since it targets the code path with UBIFS encryption available.
-- Thanks, //richard
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