Messages in this thread | | | From | Jean-Marc Eurin <> | Date | Thu, 3 Feb 2022 17:53:47 -0800 | Subject | Re: [PATCH v2] mtdoops: Fix the size of the header read buffer. |
| |
On Mon, Jan 31, 2022 at 2:00 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote: > > Hi Jean-Marc, > > jmeurin@google.com wrote on Fri, 28 Jan 2022 14:01:56 -0800: > > > The read buffer size depends on the MTDOOPS_HEADER_SIZE. > > > > Tested: Changed the header size, it doesn't panic, header is still > > read/written correctly. > > On what Linux kernel version are you? It looks like we don't share the > same code base, are we?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/mtd/mtdoops.c?h=v5.17-rc2 has that bug. If you try to increase the MTDOOPS_HEADER_SIZE, find_next_position() will try to do an mtd_read() of MTDOOPS_HEADER_SIZE bytes in a count buffer that is fixed to only 8 bytes.
Thanks,
Jean-Marc
> > > > > Signed-off-by: Jean-Marc Eurin <jmeurin@google.com> > > --- > > drivers/mtd/mtdoops.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c > > index 227df24387df..09a26747f490 100644 > > --- a/drivers/mtd/mtdoops.c > > +++ b/drivers/mtd/mtdoops.c > > @@ -223,7 +223,7 @@ static void find_next_position(struct mtdoops_context *cxt) > > { > > struct mtd_info *mtd = cxt->mtd; > > int ret, page, maxpos = 0; > > - u32 count[2], maxcount = 0xffffffff; > > + u32 count[MTDOOPS_HEADER_SIZE/sizeof(u32)], maxcount = 0xffffffff; > > size_t retlen; > > > > for (page = 0; page < cxt->oops_pages; page++) { > > > Thanks, > Miquèl
| |