main.c
[ZBX-10493] Potential memory leak in case of retries in web-scenarios Created: 2016 Mar 03 Updated: 2017 May 30 Resolved: 2016 Apr 06 |
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| Status: | Closed |
| Project: | ZABBIX BUGS AND ISSUES |
| Component/s: | Server (S) |
| Affects Version/s: | 2.2.11 |
| Fix Version/s: | 2.2.12rc1, 3.0.2rc1, 3.2.0alpha1 |
| Type: | Incident report | Priority: | Minor |
| Reporter: | Sandis Neilands (Inactive) | Assignee: | Unassigned |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | curl, memoryleak | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Attachments: |
main.c
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| Description |
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From process_httptest():
/* try to retrieve page several times depending on number of retries */
do
{
memset(&page, 0, sizeof(page));
if (CURLE_OK == (err = curl_easy_perform(easyhandle)))
break;
}
while (0 < --httptest->httptest.retries);
page contains dynamically-allocated write buffer data which is managed by write-callback WRITEFUNCTION2(). If it was called by the libcurl (curl_easy_perform()) but the (re)try failed then we'll lose the allocated memory (data set to 0 with memset()). |
| Comments |
| Comment by Viktors Tjarve [ 2016 Apr 04 ] |
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Attached main.c - a simple program to repeat this memory leak. Compile main.c with debbuging and libcurl gcc main.c -g -lcurl Memory leak Valgrind test result: ==4664== HEAP SUMMARY: ==4664== in use at exit: 2,308,362 bytes in 3,157 blocks ==4664== total heap usage: 11,038 allocs, 7,881 frees, 4,591,392 bytes allocated ==4664== ==4664== 2,072,576 bytes in 1 blocks are definitely lost in loss record 644 of 644 ==4664== at 0x4C2CE8E: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==4664== by 0x400D5A: zbx_strncpy_alloc (main.c:37) ==4664== by 0x400E4D: WRITEFUNCTION2 (main.c:61) ==4664== by 0x4E4BCCF: Curl_client_write (in /usr/lib/x86_64-linux-gnu/libcurl.so.4.3.0) ==4664== by 0x4E6073F: Curl_readwrite (in /usr/lib/x86_64-linux-gnu/libcurl.so.4.3.0) ==4664== by 0x4E69ACB: multi_runsingle (in /usr/lib/x86_64-linux-gnu/libcurl.so.4.3.0) ==4664== by 0x4E6A270: curl_multi_perform (in /usr/lib/x86_64-linux-gnu/libcurl.so.4.3.0) ==4664== by 0x4E618A2: curl_easy_perform (in /usr/lib/x86_64-linux-gnu/libcurl.so.4.3.0) ==4664== by 0x401122: main (main.c:169) ==4664== ==4664== LEAK SUMMARY: ==4664== definitely lost: 2,072,576 bytes in 1 blocks ==4664== indirectly lost: 0 bytes in 0 blocks ==4664== possibly lost: 0 bytes in 0 blocks ==4664== still reachable: 235,786 bytes in 3,156 blocks ==4664== suppressed: 0 bytes in 0 blocks ==4664== Reachable blocks (those to which a pointer was found) are not shown. ==4664== To see them, rerun with: --leak-check=full --show-leak-kinds=all ==4664== ==4664== For counts of detected and suppressed errors, rerun with: -v ==4664== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0) |
| Comment by Viktors Tjarve [ 2016 Apr 04 ] |
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Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-10493 |
| Comment by Sandis Neilands (Inactive) [ 2016 Apr 05 ] |
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Successfully tested with minor improvement in r59288. Just note that the development branch is based on 2.2 but fix version mentions only 3+. Also no such problem for EzTexting since there are no retries. |
| Comment by Viktors Tjarve [ 2016 Apr 06 ] |
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Released in:
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