================================================================= ==26633==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6040000e593f at pc 0x7f7a08ddfe55 bp 0x7f79e5feb3d0 sp 0x7f79e5feab78 WRITE of size 53 at 0x6040000e593f thread T31 llvm-symbolizer: for the -functions option: Cannot find option named 'true'! #0 0x7f7a08ddfe54 in realpath /usr/src/debug/gcc-6.1.1-20160817/obj-x86_64-redhat-linux/x86_64-redhat-linux/libsanitizer/asan/../../../../libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:2810 #1 0x43e4be in check_plugin_path /home/william/development/389ds/ds/ldap/servers/slapd/fedse.c:1960 #2 0x7f7a08912e7f in dse_call_callback /home/william/development/389ds/ds/ldap/servers/slapd/dse.c:2634 #3 0x7f7a08911c1c in dse_add /home/william/development/389ds/ds/ldap/servers/slapd/dse.c:2332 #4 0x7f7a088d0910 in op_shared_add /home/william/development/389ds/ds/ldap/servers/slapd/add.c:700 #5 0x7f7a088ced65 in do_add /home/william/development/389ds/ds/ldap/servers/slapd/add.c:227 #6 0x41f5eb in connection_dispatch_operation /home/william/development/389ds/ds/ldap/servers/slapd/connection.c:612 #7 0x4250e6 in connection_threadmain /home/william/development/389ds/ds/ldap/servers/slapd/connection.c:1759 #8 0x7f7a05dcc7de in _pt_root /usr/src/debug/nspr-4.12.0/pr/src/pthreads/../../../nspr/pr/src/pthreads/ptthread.c:216 #9 0x7f7a05b8c6b9 in start_thread pthread_create.c:? #10 0x7f7a058c73ce in __GI___clone :? 0x6040000e593f is located 0 bytes to the right of 47-byte region [0x6040000e5910,0x6040000e593f) allocated by thread T31 here: #0 0x7f7a08e48f00 in malloc _asan_rtl_ #1 0x7f7a088eb79c in slapi_ch_malloc /home/william/development/389ds/ds/ldap/servers/slapd/ch_malloc.c:113 #2 0x43e4a7 in check_plugin_path /home/william/development/389ds/ds/ldap/servers/slapd/fedse.c:1959 #3 0x7f7a08912e7f in dse_call_callback /home/william/development/389ds/ds/ldap/servers/slapd/dse.c:2634 #4 0x7f7a08911c1c in dse_add /home/william/development/389ds/ds/ldap/servers/slapd/dse.c:2332 #5 0x7f7a088d0910 in op_shared_add /home/william/development/389ds/ds/ldap/servers/slapd/add.c:700 #6 0x7f7a088ced65 in do_add /home/william/development/389ds/ds/ldap/servers/slapd/add.c:227 #7 0x41f5eb in connection_dispatch_operation /home/william/development/389ds/ds/ldap/servers/slapd/connection.c:612 #8 0x4250e6 in connection_threadmain /home/william/development/389ds/ds/ldap/servers/slapd/connection.c:1759 #9 0x7f7a05dcc7de in _pt_root /usr/src/debug/nspr-4.12.0/pr/src/pthreads/../../../nspr/pr/src/pthreads/ptthread.c:216 Thread T31 created by T0 here: #0 0x7f7a08db3538 in pthread_create _asan_rtl_ #1 0x7f7a05dcc4ba in _PR_CreateThread /usr/src/debug/nspr-4.12.0/pr/src/pthreads/../../../nspr/pr/src/pthreads/ptthread.c:457 SUMMARY: AddressSanitizer: heap-buffer-overflow (/lib64/libasan.so.3+0x5de54) Shadow bytes around the buggy address: 0x0c0880014ad0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c0880014ae0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c0880014af0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c0880014b00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c0880014b10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa =>0x0c0880014b20: fa fa 00 00 00 00 00[07]fa fa 00 00 00 00 02 fa 0x0c0880014b30: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa 0x0c0880014b40: fa fa fd fd fd fd fd fa fa fa 00 00 00 00 02 fa 0x0c0880014b50: fa fa 00 00 00 00 00 fa fa fa 00 00 00 00 04 fa 0x0c0880014b60: fa fa 00 00 00 00 04 fa fa fa 00 00 00 00 02 fa 0x0c0880014b70: fa fa 00 00 00 00 02 fa fa fa fd fd fd fd fd fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Heap right redzone: fb Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack partial redzone: f4 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==26633==ABORTING
Isn't it false positive? full_path stores a full path which could contain some redundancies (e.g., '//'). realpath normalizes them and compacts the path? {{{ 1954 if ( vals[j] == '/' ) { / absolute path / 1955 full_path = slapi_get_plugin_name(NULL, vals[j]); 1956 } else { / relative path */ 1957 full_path = slapi_get_plugin_name(PLUGINDIR, vals[j]); 1958 } 1959 resolved_path = slapi_ch_malloc(strlen(full_path) + 1); 1960 res = realpath( full_path, resolved_path ); }}}
The plugin it affected had the name:
{{{ nsslapd-pluginPath: libro_replica nsslapd-pluginPath: libhellorust }}}
So I'm not really sure why this happened. I'll investigate further ....
Okay, the issue is in how we use realpath. The plugin is found as:
{{{ (gdb) print full_path $3 = 0x6060001d61e0 "/opt/dirsrv/lib/dirsrv/plugins/libhellorust.so" }}}
However, this is a versioned .so, so it's actually a symlink. When it's expanded, we go to:
{{{ (gdb) print res $1 = 0x6040000f7910 "/opt/dirsrv/lib/dirsrv/plugins/libhellorust-0.1.0.so" }}}
However, with realpath we are providing it the buffer to allocate into:
{{{ resolved_path = slapi_ch_malloc(strlen(full_path) + 1); res = realpath( full_path, resolved_path ); }}}
This buffer is too small, thus the overflow occurs.
Either we can allocate 6 extra chars ((full_path) + 7) to fit in the "-0.0.0", or we can pass NULL to realpath, and just use free() on the result, rather than slapi_ch_free().
Given the symbol version could be valid as "-0.10.0" or even "-100.100.100", I think any static allocation scheme will fail. We should probably just dynamically allocate this, and use free().
attachment 0001-Ticket-48982-Enabling-a-plugin-that-has-a-versioned-.patch
Looks good!
According to the man page: {{{ The free() function frees the memory space pointed to by ptr, which must have been returned by a previous call to malloc(), calloc(), or realloc(). Otherwise, or if free(ptr) has already been called before, undefined behavior occurs. If ptr is NULL, no operation is performed. }}} the following NULL check is no longer needed? {{{ 1981 if (res != NULL) { }}} If you are uncomfortable to remove the check, can we use slapi_ch_free_string instead of pure free although res was not malloc'ed slapi_ch_*alloc?
Otherwise, you have my ack.
commit 31c0425 Compressing objects: 100% (13/13), done. Writing objects: 100% (13/13), 1.90 KiB | 0 bytes/s, done. Total 13 (delta 9), reused 0 (delta 0) To ssh://git.fedorahosted.org/git/389/ds.git 04a9c89..31c0425 master -> master
commit 617b64f Compressing objects: 100% (6/6), done. Writing objects: 100% (6/6), 690 bytes | 0 bytes/s, done. Total 6 (delta 4), reused 0 (delta 0) To ssh://git.fedorahosted.org/git/389/ds.git 31c0425..617b64f master -> master
commit d945aba Writing objects: 100% (6/6), 1.01 KiB | 0 bytes/s, done. Total 6 (delta 4), reused 0 (delta 0) To ssh://git.fedorahosted.org/git/389/ds.git 9d66d3f..d945aba master -> master
Metadata Update from @firstyear: - Issue assigned to firstyear - Issue set to the milestone: 1.3.6 backlog
389-ds-base is moving from Pagure to Github. This means that new issues and pull requests will be accepted only in 389-ds-base's github repository.
This issue has been cloned to Github and is available here: - https://github.com/389ds/389-ds-base/issues/2041
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Metadata Update from @spichugi: - Issue close_status updated to: wontfix (was: Fixed)
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