Using min_t(int, ...) as a potential array index implies to the compiler that negative offsets should be allowed. This is not the case, though. Replace "int" with "unsigned int". Fixes the following warning exposed under future CONFIG_FORTIFY_SOURCE improvements:
In file included from include/linux/string.h:253, from include/linux/bitmap.h:11, from include/linux/cpumask.h:12, from include/linux/smp.h:13, from include/linux/lockdep.h:14, from include/linux/rcupdate.h:29, from include/linux/rculist.h:11, from include/linux/pid.h:5, from include/linux/sched.h:14, from include/linux/delay.h:23, from drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:35: drivers/net/ethernet/chelsio/cxgb4/t4_hw.c: In function 't4_get_raw_vpd_params': include/linux/fortify-string.h:46:33: warning: '__builtin_memcpy' pointer overflow between offset 29 and size [2147483648, 4294967295] [-Warray-bounds] 46 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:388:9: note: in expansion of macro '__underlying_memcpy' 388 | __underlying_##op(p, q, __fortify_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:433:26: note: in expansion of macro '__fortify_memcpy_chk' 433 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2796:9: note: in expansion of macro 'memcpy' 2796 | memcpy(p->id, vpd + id, min_t(int, id_len, ID_LEN)); | ^~~~~~ include/linux/fortify-string.h:46:33: warning: '__builtin_memcpy' pointer overflow between offset 0 and size [2147483648, 4294967295] [-Warray-bounds] 46 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:388:9: note: in expansion of macro '__underlying_memcpy' 388 | __underlying_##op(p, q, __fortify_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:433:26: note: in expansion of macro '__fortify_memcpy_chk' 433 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2798:9: note: in expansion of macro 'memcpy' 2798 | memcpy(p->sn, vpd + sn, min_t(int, sn_len, SERNUM_LEN)); | ^~~~~~
Additionally remove needless cast from u8[] to char * in last strim() call.
Reported-by: kernel test robot lkp@intel.com Link: https://lore.kernel.org/lkml/202205031926.FVP7epJM-lkp@intel.com Fixes: fc9279298e3a ("cxgb4: Search VPD with pci_vpd_find_ro_info_keyword()") Fixes: 24c521f81c30 ("cxgb4: Use pci_vpd_find_id_string() to find VPD ID string") Cc: Raju Rangoju rajur@chelsio.com Cc: "David S. Miller" davem@davemloft.net Cc: Eric Dumazet edumazet@google.com Cc: Jakub Kicinski kuba@kernel.org Cc: Paolo Abeni pabeni@redhat.com Cc: netdev@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Kees Cook keescook@chromium.org --- v1: https://lore.kernel.org/lkml/20220503144425.2858110-1-keescook@chromium.org/ v2: use min_t again. --- drivers/net/ethernet/chelsio/cxgb4/t4_hw.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c index e7b4e3ed056c..8d719f82854a 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c +++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c @@ -2793,14 +2793,14 @@ int t4_get_raw_vpd_params(struct adapter *adapter, struct vpd_params *p) goto out; na = ret;
- memcpy(p->id, vpd + id, min_t(int, id_len, ID_LEN)); + memcpy(p->id, vpd + id, min_t(unsigned int, id_len, ID_LEN)); strim(p->id); - memcpy(p->sn, vpd + sn, min_t(int, sn_len, SERNUM_LEN)); + memcpy(p->sn, vpd + sn, min_t(unsigned int, sn_len, SERNUM_LEN)); strim(p->sn); - memcpy(p->pn, vpd + pn, min_t(int, pn_len, PN_LEN)); + memcpy(p->pn, vpd + pn, min_t(unsigned int, pn_len, PN_LEN)); strim(p->pn); - memcpy(p->na, vpd + na, min_t(int, na_len, MACADDR_LEN)); - strim((char *)p->na); + memcpy(p->na, vpd + na, min_t(unsigned int, na_len, MACADDR_LEN)); + strim(p->na);
out: vfree(vpd);
Hello:
This patch was applied to netdev/net.git (master) by Jakub Kicinski kuba@kernel.org:
On Thu, 5 May 2022 16:31:01 -0700 you wrote:
Using min_t(int, ...) as a potential array index implies to the compiler that negative offsets should be allowed. This is not the case, though. Replace "int" with "unsigned int". Fixes the following warning exposed under future CONFIG_FORTIFY_SOURCE improvements:
In file included from include/linux/string.h:253, from include/linux/bitmap.h:11, from include/linux/cpumask.h:12, from include/linux/smp.h:13, from include/linux/lockdep.h:14, from include/linux/rcupdate.h:29, from include/linux/rculist.h:11, from include/linux/pid.h:5, from include/linux/sched.h:14, from include/linux/delay.h:23, from drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:35: drivers/net/ethernet/chelsio/cxgb4/t4_hw.c: In function 't4_get_raw_vpd_params': include/linux/fortify-string.h:46:33: warning: '__builtin_memcpy' pointer overflow between offset 29 and size [2147483648, 4294967295] [-Warray-bounds] 46 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:388:9: note: in expansion of macro '__underlying_memcpy' 388 | __underlying_##op(p, q, __fortify_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:433:26: note: in expansion of macro '__fortify_memcpy_chk' 433 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2796:9: note: in expansion of macro 'memcpy' 2796 | memcpy(p->id, vpd + id, min_t(int, id_len, ID_LEN)); | ^~~~~~ include/linux/fortify-string.h:46:33: warning: '__builtin_memcpy' pointer overflow between offset 0 and size [2147483648, 4294967295] [-Warray-bounds] 46 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:388:9: note: in expansion of macro '__underlying_memcpy' 388 | __underlying_##op(p, q, __fortify_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:433:26: note: in expansion of macro '__fortify_memcpy_chk' 433 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:2798:9: note: in expansion of macro 'memcpy' 2798 | memcpy(p->sn, vpd + sn, min_t(int, sn_len, SERNUM_LEN)); | ^~~~~~
[...]
Here is the summary with links: - [v2] net: chelsio: cxgb4: Avoid potential negative array offset https://git.kernel.org/netdev/net/c/1c7ab9cd98b7
You are awesome, thank you!
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