diff mbox series

[RFC] resolv: Align buf before second query for A_AAA in __res_context_query

Message ID 20231130112430.23815-2-ludwig.rydberg@gaisler.com
State Changes Requested
Headers
Series [RFC] resolv: Align buf before second query for A_AAA in __res_context_query |

Checks

Context Check Description
redhat-pt-bot/TryBot-apply_patch success Patch applied to master at the time it was sent
redhat-pt-bot/TryBot-32bit success Build for i686
linaro-tcwg-bot/tcwg_glibc_build--master-arm success Testing passed
linaro-tcwg-bot/tcwg_glibc_build--master-aarch64 success Testing passed
linaro-tcwg-bot/tcwg_glibc_check--master-arm success Testing passed
linaro-tcwg-bot/tcwg_glibc_check--master-aarch64 success Testing passed

Commit Message

Ludwig Rydberg Nov. 30, 2023, 11:24 a.m. UTC 
  Re-introduces alignment handling that was removed by patch 40c0add7d487
("resolve: Remove __res_context_query alloca usage")

Verfied by successfully running the resolv test suite on sparc32.

Signed-off-by: Ludwig Rydberg <ludwig.rydberg@gaisler.com>
---
 resolv/res_query.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/resolv/res_query.c b/resolv/res_query.c
index 1b148a2a05b8..d065814b38e8 100644
--- a/resolv/res_query.c
+++ b/resolv/res_query.c
@@ -147,9 +147,19 @@  __res_context_query (struct resolv_context *ctx, const char *name,
 		  }
 
 		nquery1 = n;
-		query2 = buf.data + n;
+		/* Align the buffer.  */
+		int npad = ((nquery1 + __alignof__ (HEADER) - 1)
+			    & ~(__alignof__ (HEADER) - 1)) - nquery1;
+		if (n > buf.length - npad)
+		  {
+		    n = -1;
+		    goto unspec_nomem;
+		  }
+
+		int nused = n + npad;
+		query2 = buf.data + nused;
 		n = __res_context_mkquery (ctx, QUERY, name, class, T_AAAA,
-					   NULL, query2, buf.length - n);
+					   NULL, query2, buf.length - nused);
 		if (n > 0
 		    && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0)
 		  /* Use RESOLV_EDNS_BUFFER_SIZE because the receive