Commit d37322a4 authored Oct 21, 2009 by Yi Zou Committed by James Bottomley Dec 04, 2009

[SCSI] libfc: Fix frags in frame exceeding SKB_MAX_FRAGS in fc_fcp_send_data

In case of sequence offload, in fc_fcp_send_data(), the skb_fill_page_info()
called may end up adding more frags to the skb_shinfo(fp_skb(fp))->frags[],
exceeding SKB_MAX_FRAGS, this eventually corrupts the memory. I am adding the
FR_FRAME_SG_LEN back, but as SKB_MAX_FRAGS -1, leaving 1 for our fcoe_eof_crc
page. And send will be broken into multiple large sends if the frame already
contains more frags than skb handle.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

parent 7221d7e5

drivers/scsi/libfc/fc_fcp.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -574,7 +574,8 @@ static int fc_fcp_send_data(struct fc_fcp_pkt fsp, struct fc_seq seq,
		tlen -= sg_bytes;
		remaining -= sg_bytes;

		if (tlen)
		if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
		(tlen))
		continue;

		/*

include/scsi/fc_frame.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -37,6 +37,9 @@
		#define FC_FRAME_HEADROOM 32 /* headroom for VLAN + FCoE headers */
		#define FC_FRAME_TAILROOM 8 /* trailer space for FCoE */

		/* Max number of skb frags allowed, reserving one for fcoe_crc_eof page */
		#define FC_FRAME_SG_LEN (MAX_SKB_FRAGS - 1)

		#define fp_skb(fp) (&((fp)->skb))
		#define fr_hdr(fp) ((fp)->skb.data)
		#define fr_len(fp) ((fp)->skb.len)