Bugs in the internal record compression routines [CORE3115]

[firebird-automations]

Submitted by: @ibprovider

1. SQZ_decompress

while (input < last)
{
const int len = (signed char) *input++;

if (len < 0)
{
if(input == last) // <----- !!!
{
BUGCHECK(179); //! \todo Use an other BUGCHECK code
}

const UCHAR c = \*input\+\+;

---------
2. SQZ_differences

while (end1 - rec1 > 2)
{
if (rec1[0] != rec2[0] || rec1[1] != rec2[1])
{
p = out++;
/* cast this to LONG to take care of OS/2 pointer arithmetic
when rec1 is at the end of a segment, to avoid wrapping around */

const SCHAR* yellow = (SCHAR *) MIN((U_IPTR) end1, ((U_IPTR) rec1 + 127)) - 1;

while ( (rec1 <= yellow && rec1[0] != rec2[0]) ||
(/*1*/ rec1 < yellow /*1*/ && /*2*/ rec1[1] != rec2[1] /*2*/) ) // <----- !!!
{

Commits: da81e6b f535bb8 db34472

[firebird-automations]

Modified by: @AlexPeshkoff

assignee: Alexander Peshkov [ alexpeshkoff ]

[firebird-automations]

Modified by: @AlexPeshkoff

status: Open [ 1 ] => Open [ 1 ]

Target: 2.1.4, 3.0 Alpha 1, 2.0.7 [ 10361, 10331, 10390 ]

[firebird-automations]

Commented by: @AlexPeshkoff

Issue appears to be critical, cause it can in rare cases make firebird terminate due to access violation.

[firebird-automations]

Modified by: @AlexPeshkoff

status: Open [ 1 ] => Resolved [ 5 ]

resolution: Fixed [ 1 ]

Fix Version: 2.5.0 [ 10221 ]

[firebird-automations]

Modified by: @dyemanov

summary: BUGs[?] in sqz.cpp functions => Bugs in the internal record compression routines

[firebird-automations]

Commented by: @ibprovider

Please, apply these changes to
- Compressor::unpack
- Compressor::makeDiff

[firebird-automations]

Commented by: @AlexPeshkoff

Reopening for front- and backporting

[firebird-automations]

Modified by: @AlexPeshkoff

status: Resolved [ 5 ] => Reopened [ 4 ]

resolution: Fixed [ 1 ] =>

[firebird-automations]

Modified by: @AlexPeshkoff

status: Reopened [ 4 ] => Reopened [ 4 ]

Target: 2.1.4, 3.0 Alpha 1, 2.0.7 [ 10361, 10331, 10390 ] =>

[firebird-automations]

Modified by: @AlexPeshkoff

status: Reopened [ 4 ] => Resolved [ 5 ]

resolution: Fixed [ 1 ]

Fix Version: 2.1.4 [ 10361 ]

Fix Version: 3.0 Alpha 1 [ 10331 ]

Fix Version: 2.0.7 [ 10390 ]

[firebird-automations]

Modified by: @pcisar

status: Resolved [ 5 ] => Closed [ 6 ]

[firebird-automations]

Modified by: @pavel-zotov

QA Status: No test

[firebird-automations]

Modified by: @pavel-zotov

status: Closed [ 6 ] => Closed [ 6 ]

QA Status: No test => Cannot be tested

[firebird-automations]

Commented by: @ibprovider

Pavel, I think, in general case, for similar code/problem need create the "unit tests" on C++.

Through isql/api, of course, internal code can not be verified.

[firebird-automations]

Commented by: @pavel-zotov

IMO, one need to add several new items into "QA Status" combo...

[firebird-automations]

Commented by: @ibprovider

And subdir "firebird\trunc\tests" :-)