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Subjectdata corruption in 2.4.19/drivers/scsi/sg.c
Hi,

As subject suggests generic scsi module from 2.4.19 corrupts data.
Backing back to 2.4.18 code [as suggested below] fixes the problem.
From the attached patch it's not clear what's causing the problem
as the code appears equivalent. Corruption occurs if you break out
the inner loop few lines later:

if (ksglen > usglen) {
...
p += usglen;
ksglen -= usglen;
break;
}

and reenter it. Then ksglen and p are reset which results in some
duplicate data injection.

Cheers. Andy.

--- ./drivers/scsi/sg.c.orig Sat Aug 3 02:39:44 2002
+++ ./drivers/scsi/sg.c Wed Aug 21 00:44:16 2002
@@ -1884,11 +1884,16 @@
res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
if (res) return res;

+#if 0
for (; k < schp->k_use_sg; ++k, ++sclp) {
ksglen = (int)sclp->length;
p = sclp->address;
if (NULL == p)
break;
+#else
+ for (; (k < schp->k_use_sg) && p;
+ ++k, ++sclp, ksglen = (int)sclp->length, p = sclp->address) {
+#endif
ok = (SG_USER_MEM != mem_src_arr[k]);
if (usglen <= 0)
break;
@@ -2040,11 +2045,16 @@
res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
if (res) return res;

+#if 0
for (; k < schp->k_use_sg; ++k, ++sclp) {
ksglen = (int)sclp->length;
p = sclp->address;
if (NULL == p)
break;
+#else
+ for (; (k < schp->k_use_sg) && p;
+ ++k, ++sclp, ksglen = (int)sclp->length, p = sclp->address) {
+#endif
ok = (SG_USER_MEM != mem_src_arr[k]);
if (usglen <= 0)
break;
-
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