diff mbox series

[net,2/4] sctp: add size validation when walking chunks

Message ID 1f204ae1a2b2dfe6ea49fd9fdd583a4d02a70542.1624904195.git.marcelo.leitner@gmail.com (mailing list archive)
State Accepted
Commit 50619dbf8db77e98d821d615af4f634d08e22698
Delegated to: Netdev Maintainers
Headers show
Series sctp: add some size validations | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present fail Series targets non-next tree, but doesn't contain any Fixes tags
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net
netdev/subject_prefix success Link
netdev/cc_maintainers warning 2 maintainers not CCed: davem@davemloft.net kuba@kernel.org
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/header_inline success Link

Commit Message

Marcelo Ricardo Leitner June 28, 2021, 7:13 p.m. UTC
The first chunk in a packet is ensured to be present at the beginning of
sctp_rcv(), as a packet needs to have at least 1 chunk. But the second
one, may not be completely available and ch->length can be over
uninitialized memory.

Fix here is by only trying to walk on the next chunk if there is enough to
hold at least the header, and then proceed with the ch->length validation
that is already there.

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
---
 net/sctp/input.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 8924e2e142c8234dac233e56e923110e266c9834..f72bff93745c44be0dbfa29e754f2872a7d874c2 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -1247,7 +1247,7 @@  static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net,
 
 		ch = (struct sctp_chunkhdr *)ch_end;
 		chunk_num++;
-	} while (ch_end < skb_tail_pointer(skb));
+	} while (ch_end + sizeof(*ch) < skb_tail_pointer(skb));
 
 	return asoc;
 }