From eef7d739c218cb2546cf95686db77de0d76e4122 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 25 Jan 2008 00:58:46 -0500 Subject: dlm: dlm_process_incoming_buffer() fixes * check that length is large enough to cover the non-variable part of message or rcom resp. (after checking that it's large enough to cover the header, of course). * kill more pointless casts Signed-off-by: Al Viro Signed-off-by: David Teigland --- fs/dlm/midcomms.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) (limited to 'fs/dlm/midcomms.c') diff --git a/fs/dlm/midcomms.c b/fs/dlm/midcomms.c index e69926e984db..07ac709f3ed7 100644 --- a/fs/dlm/midcomms.c +++ b/fs/dlm/midcomms.c @@ -61,9 +61,9 @@ int dlm_process_incoming_buffer(int nodeid, const void *base, union { unsigned char __buf[DLM_INBUF_LEN]; /* this is to force proper alignment on some arches */ - struct dlm_header dlm; + union dlm_packet p; } __tmp; - struct dlm_header *msg = &__tmp.dlm; + union dlm_packet *p = &__tmp.p; int ret = 0; int err = 0; uint16_t msglen; @@ -75,15 +75,22 @@ int dlm_process_incoming_buffer(int nodeid, const void *base, message may wrap around the end of the buffer back to the start, so we need to use a temp buffer and copy_from_cb. */ - copy_from_cb(msg, base, offset, sizeof(struct dlm_header), + copy_from_cb(p, base, offset, sizeof(struct dlm_header), limit); - msglen = le16_to_cpu(msg->h_length); - lockspace = msg->h_lockspace; + msglen = le16_to_cpu(p->header.h_length); + lockspace = p->header.h_lockspace; err = -EINVAL; if (msglen < sizeof(struct dlm_header)) break; + if (p->header.h_cmd == DLM_MSG) { + if (msglen < sizeof(struct dlm_message)) + break; + } else { + if (msglen < sizeof(struct dlm_rcom)) + break; + } err = -E2BIG; if (msglen > dlm_config.ci_buffer_size) { log_print("message size %d from %d too big, buf len %d", @@ -104,26 +111,26 @@ int dlm_process_incoming_buffer(int nodeid, const void *base, in the buffer on the stack (which should work for most ordinary messages). */ - if (msglen > DLM_INBUF_LEN && msg == &__tmp.dlm) { - msg = kmalloc(dlm_config.ci_buffer_size, GFP_KERNEL); - if (msg == NULL) + if (msglen > sizeof(__tmp) && p == &__tmp.p) { + p = kmalloc(dlm_config.ci_buffer_size, GFP_KERNEL); + if (p == NULL) return ret; } - copy_from_cb(msg, base, offset, msglen, limit); + copy_from_cb(p, base, offset, msglen, limit); - BUG_ON(lockspace != msg->h_lockspace); + BUG_ON(lockspace != p->header.h_lockspace); ret += msglen; offset += msglen; offset &= (limit - 1); len -= msglen; - dlm_receive_buffer(msg, nodeid); + dlm_receive_buffer(p, nodeid); } - if (msg != &__tmp.dlm) - kfree(msg); + if (p != &__tmp.p) + kfree(p); return err ? err : ret; } -- cgit v1.2.3