This is a note to let you know that I've just added the patch titled EDAC/thunderx: Fix possible out-of-bounds string access to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: edac-thunderx-fix-possible-out-of-bounds-string-acce.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit fd34e87d9e8e7c5419539b39f3e988cea2f22abc Author: Arnd Bergmann <arnd@xxxxxxxx> Date: Wed Nov 22 23:19:53 2023 +0100 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 <arnd@xxxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Link: https://lore.kernel.org/r/20231122222007.3199885-1-arnd@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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);