parse_pack_header_option(): avoid unaligned memory writes
In order to recreate a pack header in our in-memory buffer, we cast the buffer to a "struct pack_header" and assign the individual fields. This is reported to cause SIGBUS on sparc64 due to alignment issues. We can work around this by using put_be32() which will write individual bytes into the buffer. Reported-by: Koakuma <koachan@protonmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King committed
Jan 19, 2025 at 08:23 UTC
4f02f4d68d8eefe728008974640839ef6e1b2182
1 file changed
+9
-6
packfile.c
+9
-6
@@ -2297,17 +2297,20 @@ int is_promisor_object(const struct object_id *oid)
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int parse_pack_header_option(const char *in, unsigned char *out, unsigned int *len)
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{
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- struct pack_header *hdr;
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+ unsigned char *hdr;
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char *c;
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- hdr = (struct pack_header *)out;
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- hdr->hdr_signature = htonl(PACK_SIGNATURE);
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- hdr->hdr_version = htonl(strtoul(in, &c, 10));
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+ hdr = out;
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+ put_be32(hdr, PACK_SIGNATURE);
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+ hdr += 4;
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+ put_be32(hdr, strtoul(in, &c, 10));
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+ hdr += 4;
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if (*c != ',')
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return -1;
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- hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
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+ put_be32(hdr, strtoul(c + 1, &c, 10));
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+ hdr += 4;
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if (*c)
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return -1;
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- *len = sizeof(*hdr);
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+ *len = hdr - out;
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return 0;
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}