From 1c7ab9cd98b78bef1657a5db7204d8d437e24c94 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 5 May 2022 16:31:01 -0700 Subject: [PATCH] net: chelsio: cxgb4: Avoid potential negative array offset 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 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 Cc: Eric Dumazet Cc: Paolo Abeni Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220505233101.1224230-1-keescook@chromium.org Signed-off-by: Jakub Kicinski --- 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 e7b4e3e..8d719f8 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); -- 2.7.4