On Sun, Aug 05, 2007 at 09:03:23PM -0500, Dave Boutcher wrote: > > /proc/pid/pagemap has a header (usually 8 bytes) the length > of which needs to be compensated for when converting from > proc file offset to page number. The calculation of the > starting page number (svpfn) compensates for this, but the > calculation of the ending page number (evpfn) does not, resulting > in reads returning 8 bytes more than were asked for and > nastily overwriting userspace memory.
Does this mean you're running on a 64-bit arch? I'd already fixed this locally, but it was off by 4 for me. Acked-by: Matt Mackall <[EMAIL PROTECTED]> > Diffed against 2.6.23-rc1-mm2 > > Signed-off-by: Dave Boutcher <[EMAIL PROTECTED]> > --- > fs/proc/task_mmu.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index 4594f15..b2baeab 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -627,7 +627,7 @@ static ssize_t pagemap_read(struct file *file, char > __user *buf, > addr = PAGE_SIZE * svpfn; > if ((svpfn + 1) * sizeof(unsigned long) != src) > goto out; > - evpfn = min((src + count) / sizeof(unsigned long), > + evpfn = min((src + count) / sizeof(unsigned long) - 1, > ((~0UL) >> PAGE_SHIFT) + 1); > count = (evpfn - svpfn) * sizeof(unsigned long); > end = PAGE_SIZE * evpfn; > -- > 1.4.4.2 -- Mathematics is the supreme nostalgia of our time. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
