Messages in this thread | | | From | Kees Cook <> | Date | Tue, 12 Feb 2019 12:27:06 -0800 | Subject | Re: [PATCH] pstore/ram: Add kmsg hlen null check to ramoops_pstore_write |
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On Thu, Jan 31, 2019 at 11:35 PM Yue Hu <huyue2@yulong.com> wrote: > > From 9385613f546a4d0b2497dc2ed22cb9475eb3621c Mon Sep 17 00:00:00 2001 > From: Yue Hu <huyue2@yulong.com> > Date: Fri, 1 Feb 2019 11:27:32 +0800 > Subject: [PATCH] pstore/ram: Add kmsg hlen null check to ramoops_pstore_write > > If null hdr happened in ramoops_write_kmsg_hdr(), that means > we cannot get the dmesg record since it will be treated as > invalid header in ramoops_pstore_read(). So we should not > execute the following code but return the error. > > Signed-off-by: Yue Hu <huyue2@yulong.com> > --- > fs/pstore/ram.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c > index 7e188f6..4a06675 100644 > --- a/fs/pstore/ram.c > +++ b/fs/pstore/ram.c > @@ -467,6 +467,9 @@ static int notrace ramoops_pstore_write(struct pstore_record *record) > > /* Build header and append record contents. */ > hlen = ramoops_write_kmsg_hdr(prz, record); > + if (!hlen) > + return -EINVAL; > + > size = record->size; > if (size + hlen > prz->buffer_size) > size = prz->buffer_size - hlen;
Yeah, this seems right. If we don't generate a header, then ramoops_pstore_read() will ignore anything written there. This probably means we need to refactor this to avoid memory allocation during the write. I'll apply this and do some follow-up changes.
Thanks!
-- Kees Cook
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