On Thu, Apr 01, 2021 at 09:49:04AM +0200, Marc Kleine-Budde wrote: > On 31.03.2021 14:59:44, coverity-bot wrote: > > This is an experimental semi-automated report about issues detected by > > Coverity from a scan of next-20210331 as part of the linux-next scan project: > > https://scan.coverity.com/projects/linux-next-weekly-scan > > > > You're getting this email because you were associated with the identified > > lines of code (noted below) that were touched by commits: > > > > None > > e0ab3dd5f98f ("can: mcp251xfd: add dev coredump support") > > > > Coverity reported the following: > > > > *** CID 1503585: Memory - illegal accesses (OVERRUN) > > /drivers/net/can/spi/mcp251xfd/mcp251xfd-dump.c: 190 in mcp251xfd_dump_rx_ring() > > 184 static void mcp251xfd_dump_rx_ring(const struct mcp251xfd_priv *priv, > > 185 struct mcp251xfd_dump_iter *iter) > > 186 { > > 187 struct mcp251xfd_rx_ring *rx_ring; > > 188 unsigned int i; > > 189 > > vvv CID 1503585: Memory - illegal accesses (OVERRUN) > > vvv Overrunning array of 1 8-byte elements at element index 1 (byte offset 15) by dereferencing pointer "priv->rx + i". > > 190 mcp251xfd_for_each_rx_ring(priv, rx_ring, i) > > 191 mcp251xfd_dump_rx_ring_one(priv, iter, rx_ring); > > mcp251xfd_for_each_rx_ring is a macro that iterates over all RX rings in > the struct mcp251xfd_priv. It's not pretty (as it uses its arguments > more than once), but it works: Ah yes; thanks! This is another "for each" macro that that confuses Coverity. I'll try to silence these... Thanks for the details and taking a look at it! -Kees > > | #define mcp251xfd_for_each_rx_ring(priv, ring, n) \ > | for ((n) = 0, (ring) = *((priv)->rx + (n)); \ > | (n) < (priv)->rx_ring_num; \ > | (n)++, (ring) = *((priv)->rx + (n))) > > For now there is only one rx ring... > > | struct mcp251xfd_priv { > | [...] > | struct mcp251xfd_rx_ring *rx[1]; > | u8 rx_ring_num; > | [...] > | } > > ...and rx_ring_num is initialized as "1". > > | for (i = 0; > | i < ARRAY_SIZE(priv->rx) && ram_free >= rx_obj_size; > | i++) { > | [...] > | } > | priv->rx_ring_num = i; > > > > 192 } > > 193 > > 194 static void mcp251xfd_dump_tx_ring(const struct mcp251xfd_priv *priv, > > 195 struct mcp251xfd_dump_iter *iter) > > > > If this is a false positive, please let us know so we can mark it as > > such, or teach the Coverity rules to be smarter. If not, please make > > sure fixes get into linux-next. :) For patches fixing this, please > > include these lines (but double-check the "Fixes" first): > > This looks indeed like a false positive to me. > > > Reported-by: coverity-bot <keescook+coverity-bot@xxxxxxxxxxxx> > > Addresses-Coverity-ID: 1503585 ("Memory - illegal accesses") > > Fixes: e0ab3dd5f98f ("can: mcp251xfd: add dev coredump support") > > regards, > Marc > > -- > Pengutronix e.K. | Marc Kleine-Budde | > Embedded Linux | https://www.pengutronix.de | > Vertretung West/Dortmund | Phone: +49-231-2826-924 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- Kees Cook
