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| author | Kees Cook <keescook@chromium.org> | 2017-07-12 23:36:01 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-13 01:26:03 +0200 |
| commit | 4c93496f18ce5044d78e4f7f9e018682a4f44b3d (patch) | |
| tree | 15b3f5ce7eb2c10f777f7054ba93fd0052e7300f | |
| parent | kexec_file: adjust declaration of kexec_purgatory (diff) | |
| download | linux-4c93496f18ce5044d78e4f7f9e018682a4f44b3d.tar.xz linux-4c93496f18ce5044d78e4f7f9e018682a4f44b3d.zip | |
IB/rxe: do not copy extra stack memory to skb
This fixes a over-read condition detected by FORTIFY_SOURCE for this
line:
memcpy(SKB_TO_PKT(skb), &ack_pkt, sizeof(skb->cb));
The error was:
In file included from ./include/linux/bitmap.h:8:0,
from ./include/linux/cpumask.h:11,
from ./include/linux/mm_types_task.h:13,
from ./include/linux/mm_types.h:4,
from ./include/linux/kmemcheck.h:4,
from ./include/linux/skbuff.h:18,
from drivers/infiniband/sw/rxe/rxe_resp.c:34:
In function 'memcpy',
inlined from 'send_atomic_ack.constprop' at drivers/infiniband/sw/rxe/rxe_resp.c:998:2,
inlined from 'acknowledge' at drivers/infiniband/sw/rxe/rxe_resp.c:1026:3,
inlined from 'rxe_responder' at drivers/infiniband/sw/rxe/rxe_resp.c:1286:10:
./include/linux/string.h:309:4: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter
__read_overflow2();
Daniel Micay noted that struct rxe_pkt_info is 32 bytes on 32-bit
architectures, but skb->cb is still 64. The memcpy() over-reads 32
bytes. This fixes it by zeroing the unused bytes in skb->cb.
Link: http://lkml.kernel.org/r/1497903987-21002-5-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Moni Shoua <monis@mellanox.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/infiniband/sw/rxe/rxe_resp.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c index 23039768f541..be944d5aa9af 100644 --- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -995,7 +995,9 @@ static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt, free_rd_atomic_resource(qp, res); rxe_advance_resp_resource(qp); - memcpy(SKB_TO_PKT(skb), &ack_pkt, sizeof(skb->cb)); + memcpy(SKB_TO_PKT(skb), &ack_pkt, sizeof(ack_pkt)); + memset((unsigned char *)SKB_TO_PKT(skb) + sizeof(ack_pkt), 0, + sizeof(skb->cb) - sizeof(ack_pkt)); res->type = RXE_ATOMIC_MASK; res->atomic.skb = skb; |