From: Chuck Lever <chuck.lever@oracle.com>
Date: Wed, 1 Jun 2022 12:46:52 -0400
Subject: [PATCH] SUNRPC: Trap RDMA segment overflows
Git-commit: f012e95b377c73c0283f009823c633104dedb337
Patch-mainline: v5.19
References: git-fixes
Prevent svc_rdma_build_writes() from walking off the end of a Write
chunk's segment array. Caught with KASAN.
The test that this fix replaces is invalid, and might have been left
over from an earlier prototype of the PCL work.
Fixes: 7a1cbfa18059 ("svcrdma: Use parsed chunk lists to construct RDMA Writes")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: NeilBrown <neilb@suse.com>
---
net/sunrpc/xprtrdma/svc_rdma_rw.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/sunrpc/xprtrdma/svc_rdma_rw.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c
@@ -438,10 +438,10 @@ svc_rdma_build_writes(struct svc_rdma_wr
unsigned int write_len;
u64 offset;
- seg = &info->wi_chunk->ch_segments[info->wi_seg_no];
- if (!seg)
+ if (info->wi_seg_no >= info->wi_chunk->ch_segcount)
goto out_overflow;
+ seg = &info->wi_chunk->ch_segments[info->wi_seg_no];
write_len = min(remaining, seg->rs_length - info->wi_seg_off);
if (!write_len)
goto out_overflow;