Bug 2053503
| Summary: | Please change struct stk sktref field type from short to int [rhel-7.9.z] | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Paulo Andrade <pandrade> | |
| Component: | ksh | Assignee: | Vincent Mihalkovič <vmihalko> | |
| Status: | CLOSED ERRATA | QA Contact: | Karel Volný <kvolny> | |
| Severity: | medium | Docs Contact: | ||
| Priority: | unspecified | |||
| Version: | 7.9 | CC: | amkulkar, kpfleming, svashisht | |
| Target Milestone: | rc | Keywords: | Reopened, Triaged, ZStream | |
| Target Release: | --- | |||
| Hardware: | All | |||
| OS: | Linux | |||
| Whiteboard: | ||||
| Fixed In Version: | ksh-20120801-144.el7_9 | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | ||
| Clone Of: | ||||
| : | 2116372 (view as bug list) | Environment: | ||
| Last Closed: | 2022-08-09 11:51:28 UTC | Type: | Bug | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Embargoed: | ||||
| Bug Depends On: | ||||
| Bug Blocks: | 2116372 | |||
The requested patch is related to this change https://github.com/ksh93/ksh/commit/56805b25af24f454cdd477609bcddc984628bc01#diff-743671e15792442098dcd4e1d0800309eafe0f038f7d07bb9074034b83298d85R79, from upstream commit https://github.com/ksh93/ksh/commit/56805b25af24f454cdd477609bcddc984628bc01: "... Make the stack more resilient by extending the stack reference counter 'stkref' from (signed) short to unsigned int. On modern systems with 32-bit ints, this extends the maximum number of elements on a stack from 2^15-1==32767 to 2^32-1==4294967295. The ref counter can never be negative, so there is no reason for signedness. sizeof(int) is defined as the size of a single CPU word, so this should not affect performance at all. On a 16-bit system (not that ksh still compiles there), this doubles the max number of entries to 2^16-1=65535." So I slightly modified requested patch (I used unsigned int instead of int): Here is scratch-build: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=43451843 and private-branch: http://pkgs.devel.redhat.com/cgit/rpms/ksh/commit/?h=private-vmihalko-rhel-7.9-bz2053503&id=339ae13cafcae16f0ec43dc48898610c568270b6 Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (ksh bug fix and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2022:5938 |
Copy&paste of the requested patch: """ diff -up ksh-20120801/src/lib/libast/misc/stk.c.orig ksh-20120801/src/lib/libast/misc/stk.c --- ksh-20120801/src/lib/libast/misc/stk.c.orig 2022-01-31 16:06:11.923069379 -0300 +++ ksh-20120801/src/lib/libast/misc/stk.c 2022-01-31 16:06:54.896802455 -0300 @@ -76,7 +76,7 @@ struct frame struct stk { _stk_overflow_ stkoverflow; /* called when malloc fails */ - short stkref; /* reference count; */ + int stkref; /* reference count; */ short stkflags; /* stack attributes */ char *stkbase; /* beginning of current stack frame */ char *stkend; /* end of current stack frame */ """ In bz#2007364 we had ksh patched to use the stack robustness patch. It "almost" corrected the problem for a customer. Unfortunately, it still kept crashing on average once every day. Customer is experimenting with a "guess" package with the above patch, and it is already more than 2 days without a crash. So, it should have had some side effect. Optionally, the code could be reviewed to check when the stkref field is increased/decreased and catch a wrap around before it happens.