Messages in this thread | | | Date | Mon, 20 Nov 2017 14:16:14 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] proc: fix /proc/*/map_files lookup |
| |
On Tue, 21 Nov 2017 00:27:06 +0300 Alexey Dobriyan <adobriyan@gmail.com> wrote:
> Current code does: > > if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) > > However sscanf() is broken garbage. > > It silently accepts whitespace between format specifiers > (did you know that?). > > It silently accepts valid strings which result in integer overflow. > > Do not use sscanf() for any even remotely reliable parsing code. > > OK > # readlink '/proc/1/map_files/55a23af39000-55a23b05b000' > /lib/systemd/systemd > > broken > # readlink '/proc/1/map_files/ 55a23af39000-55a23b05b000' > /lib/systemd/systemd > > broken > # readlink '/proc/1/map_files/55a23af39000-55a23b05b000 ' > /lib/systemd/systemd > > very broken > # readlink '/proc/1/map_files/1000000000000000055a23af39000-55a23b05b000' > /lib/systemd/systemd > > Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> > Cc: stable@kernel.org
OK, but why is this a problem worthy of backporting into -stable kernels?
| |