Messages in this thread | | | Date | Fri, 02 Feb 2018 19:33:24 -0500 (EST) | Subject | Re: [PATCH] net: cxgb4: avoid memcpy beyond end of source buffer | From | David Miller <> |
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From: Arnd Bergmann <arnd@arndb.de> Date: Fri, 2 Feb 2018 16:18:37 +0100
> Building with link-time-optimizations revealed that the cxgb4 driver does > a fixed-size memcpy() from a variable-length constant string into the > network interface name: > > In function 'memcpy', > inlined from 'cfg_queues_uld.constprop' at drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c:335:2, > inlined from 'cxgb4_register_uld.constprop' at drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c:719:9: > include/linux/string.h:350:3: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter > __read_overflow2(); > ^ > > I can see two equally workable solutions: either we use a strncpy() instead > of the memcpy() to stop at the end of the input, or we make the source buffer > fixed length as well. This implements the latter. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Not the most pleasant thing in the world, but I can't think of a better solution.
> @@ -355,7 +355,7 @@ struct cxgb4_lld_info { > }; > > struct cxgb4_uld_info { > - const char *name; > + char name[IFNAMSIZ]; > void *handle; > unsigned int nrxq; > unsigned int rxq_size;
David Laight asked how this can be the sole part of the patch.
All of these structures are initialized like:
static struct cxgb4_uld_info { .name = "foo", ... };
So changing from "const char *" to "char []" just works.
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