From 475c58e1a471e9b873e3e39958c64a2d278275c8 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 22 Nov 2023 23:19:53 +0100 Subject: [PATCH] EDAC/thunderx: Fix possible out-of-bounds string access Enabling -Wstringop-overflow globally exposes a warning for a common bug in the usage of strncat(): drivers/edac/thunderx_edac.c: In function 'thunderx_ocx_com_threaded_isr': drivers/edac/thunderx_edac.c:1136:17: error: 'strncat' specified bound 1024 equals destination size [-Werror=stringop-overflow=] 1136 | strncat(msg, other, OCX_MESSAGE_SIZE); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ... 1145 | strncat(msg, other, OCX_MESSAGE_SIZE); ... 1150 | strncat(msg, other, OCX_MESSAGE_SIZE); ... Apparently the author of this driver expected strncat() to behave the way that strlcat() does, which uses the size of the destination buffer as its third argument rather than the length of the source buffer. The result is that there is no check on the size of the allocated buffer. Change it to strlcat(). [ bp: Trim compiler output, fixup commit message. ] Fixes: 41003396f932 ("EDAC, thunderx: Add Cavium ThunderX EDAC driver") Signed-off-by: Arnd Bergmann Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20231122222007.3199885-1-arnd@kernel.org --- drivers/edac/thunderx_edac.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/edac/thunderx_edac.c b/drivers/edac/thunderx_edac.c index b9c5772da959..90d46e5c4ff0 100644 --- a/drivers/edac/thunderx_edac.c +++ b/drivers/edac/thunderx_edac.c @@ -1133,7 +1133,7 @@ static irqreturn_t thunderx_ocx_com_threaded_isr(int irq, void *irq_id) decode_register(other, OCX_OTHER_SIZE, ocx_com_errors, ctx->reg_com_int); - strncat(msg, other, OCX_MESSAGE_SIZE); + strlcat(msg, other, OCX_MESSAGE_SIZE); for (lane = 0; lane < OCX_RX_LANES; lane++) if (ctx->reg_com_int & BIT(lane)) { @@ -1142,12 +1142,12 @@ static irqreturn_t thunderx_ocx_com_threaded_isr(int irq, void *irq_id) lane, ctx->reg_lane_int[lane], lane, ctx->reg_lane_stat11[lane]); - strncat(msg, other, OCX_MESSAGE_SIZE); + strlcat(msg, other, OCX_MESSAGE_SIZE); decode_register(other, OCX_OTHER_SIZE, ocx_lane_errors, ctx->reg_lane_int[lane]); - strncat(msg, other, OCX_MESSAGE_SIZE); + strlcat(msg, other, OCX_MESSAGE_SIZE); } if (ctx->reg_com_int & OCX_COM_INT_CE) @@ -1217,7 +1217,7 @@ static irqreturn_t thunderx_ocx_lnk_threaded_isr(int irq, void *irq_id) decode_register(other, OCX_OTHER_SIZE, ocx_com_link_errors, ctx->reg_com_link_int); - strncat(msg, other, OCX_MESSAGE_SIZE); + strlcat(msg, other, OCX_MESSAGE_SIZE); if (ctx->reg_com_link_int & OCX_COM_LINK_INT_UE) edac_device_handle_ue(ocx->edac_dev, 0, 0, msg); @@ -1896,7 +1896,7 @@ static irqreturn_t thunderx_l2c_threaded_isr(int irq, void *irq_id) decode_register(other, L2C_OTHER_SIZE, l2_errors, ctx->reg_int); - strncat(msg, other, L2C_MESSAGE_SIZE); + strlcat(msg, other, L2C_MESSAGE_SIZE); if (ctx->reg_int & mask_ue) edac_device_handle_ue(l2c->edac_dev, 0, 0, msg);