From 9dbac9fdae6e3b411fc4c3fca3bf48f70609c398 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 [ Upstream commit 475c58e1a471e9b873e3e39958c64a2d278275c8 ] 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 Signed-off-by: Sasha Levin --- 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 f13674081cb6..4dca21b39bf7 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);