Messages in this thread | | | Date | Wed, 22 Nov 2023 17:07:47 -0600 | Subject | Re: [PATCH] EDAC, thunderx: fix possible out-of-bounds string access. | From | "Gustavo A. R. Silva" <> |
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On 11/22/23 16:19, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > Commit 1b56c90018f0 ("Makefile: Enable -Wstringop-overflow globally") exposes a > warning for a common bug in the usage of strncat():
Great to see this catching bugs already. :)
> > 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); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/edac/thunderx_edac.c:1145:33: error: 'strncat' specified bound 1024 equals destination size [-Werror=stringop-overflow=] > 1145 | strncat(msg, other, OCX_MESSAGE_SIZE); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/edac/thunderx_edac.c:1150:33: error: 'strncat' specified bound 1024 equals destination size [-Werror=stringop-overflow=] > 1150 | strncat(msg, other, OCX_MESSAGE_SIZE); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/edac/thunderx_edac.c: In function 'thunderx_l2c_threaded_isr': > drivers/edac/thunderx_edac.c:1899:17: error: 'strncat' specified bound 1024 equals destination size [-Werror=stringop-overflow=] > 1899 | strncat(msg, other, L2C_MESSAGE_SIZE); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/edac/thunderx_edac.c: In function 'thunderx_ocx_lnk_threaded_isr': > drivers/edac/thunderx_edac.c:1220:17: error: 'strncat' specified bound 1024 equals destination size [-Werror=stringop-overflow=] > 1220 | 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 use strncat().
s/strncat/strlcat
with that:
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Thanks! -- Gustavo
> > Fixes: 41003396f932 ("EDAC, thunderx: Add Cavium ThunderX EDAC driver") > Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> > Cc: Kees Cook <keescook@chromium.org> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > 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);
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