Created attachment 189714 [details] Patch Source file https://svnweb.freebsd.org/base/head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_acl.c (latest version r323491 at this time), line 1220, in function zfs_aclset_common have a local variable definition "zfs_acl_phys_t acl_phys;". At line 1297, the pointer to this variable (&acl_phys) is stored into the array "bulk"; then the current code block and the lifetime of "acl_phys" is ended after this, but "bulk" is still got used at line 1314. This code resulted in undefined behavior, meaning this bug may not be generally noticeable. In my test, the clang 3.4.1 on FreeBSD 10.3 amd64 won't trigger wrong behavior; however gcc 4.7 4.8 4.9 at any optimization level (except "-O0") will resulting a buggy behavior which showing to the user as: [WHR@kmod-test /testpool]$ mkdir 35 [WHR@kmod-test /testpool]$ cd 35 -bash: cd: 35: Permission denied Due the ACL is failed to store. The attached patch will fix this bug by moving the definition of "acl_phys" to the top block of the function, thus its lifetime will cover the whole function.
Source file https://svnweb.freebsd.org/base/head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_acl.c (latest version r323491 at this time), line 1220, in function zfs_aclset_common have a local variable definition "zfs_acl_phys_t acl_phys;". At line 1297, the pointer to this variable (&acl_phys) is stored into the array "bulk"; then the current code block and the lifetime of "acl_phys" is ended after this, but "bulk" is still got used at line 1314. This code resulted in undefined behavior, meaning this bug may not be generally noticeable. In my test, the clang 3.4.1 on FreeBSD 10.3 amd64 won't trigger wrong behavior; however gcc 4.7 4.8 4.9 at any optimization level (except "-O0") will resulting a buggy behavior which showing to the user as: [WHR@kmod-test /testpool]$ mkdir 35 [WHR@kmod-test /testpool]$ cd 35 -bash: cd: 35: Permission denied Due the ACL is failed to store. The attached patch will fix this bug by moving the definition of "acl_phys" to the top block of the function, thus its lifetime will cover the whole function.
Reported upstream: https://www.illumos.org/issues/8966
A commit references this bug: Author: avg Date: Wed Feb 21 14:17:07 UTC 2018 New revision: 329711 URL: https://svnweb.freebsd.org/changeset/base/329711 Log: MFV r329710: 8966 Source file zfs_acl.c, function zfs_aclset_common contains a use after end of the lifetime of a local variable illumos/illumos-gate@82693e09cc02331fa1b3b73b54b1060e73507a8d https://github.com/illumos/illumos-gate/commit/82693e09cc02331fa1b3b73b54b1060e73507a8d https://www.illumos.org/issues/8966 Reviewed by: Matt Ahrens <mahrens@delphix.com> Reviewed by: Andriy Gapon <avg@FreeBSD.org> Approved by: Richard Lowe <richlowe@richlowe.net> Author: WHR <msl0000023508@gmail.com> PR: 225162 Submitted by: WHR <msl0000023508@gmail.com> Reported by: WHR <msl0000023508@gmail.com> MFC after: 1 week Changes: _U head/sys/cddl/contrib/opensolaris/ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_acl.c
A commit references this bug: Author: avg Date: Thu Mar 1 08:30:09 UTC 2018 New revision: 330234 URL: https://svnweb.freebsd.org/changeset/base/330234 Log: MFC r329711: MFV r329710: 8966 use after end of the lifetime of a local variable PR: 225162 Changes: _U stable/10/ stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_acl.c
A commit references this bug: Author: avg Date: Thu Mar 1 08:33:20 UTC 2018 New revision: 330235 URL: https://svnweb.freebsd.org/changeset/base/330235 Log: MFC r329711: MFV r329710: 8966 use after end of the lifetime of a local variable PR: 225162 Changes: _U stable/11/ stable/11/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_acl.c