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Re: libcurl 7.21.0

From: Dan Fandrich <>
Date: Wed, 2 Apr 2014 18:47:15 +0200

On Wed, Apr 02, 2014 at 03:56:00PM +0000, Alona Rossen wrote:
> Our application crashes in libcurl with the following stack:
> Segmentation fault in addbyter at 0x22f8a1b8 ($t2)
> 0x22f8a1b8 (addbyter+0x18) 98650000 stb r3,0x0(r5)
> (dbx) where
> addbyter() at 0x22f8a1b8
> dprintf_formatf() at 0x22f8a2b4
> curl_mvsnprintf() at 0x22f8bc24
> Curl_failf() at 0x22f8d2cc
> (dbx)

Line numbers would go a long way to help track this down, as would
displaying a deeper stack trace.

> We do set NOSIGNALS option and we do use SSL library˘s mutex callbacks.
> However, we do not explicitely clear CRYPTO mutexes, since our application
> misses code similar to the following:
> static void kill_locks(void)
> {
> int i;
> CRYPTO_set_locking_callback(NULL);
> for (i=0; i<CRYPTO_num_locks(); i++)
> pthread_mutex_destroy(&(lockarray[i]));
> OPENSSL_free(lockarray);
> }

Once the locks are set, they don't need to be deleted while the program is

> Please advise.

My first advice would be to migrate to a version of curl that's not 4 years
old. Lots of bugs have been fixed since then. The second would be to try to
track down which call to Curl_failf is causing this issue, what the arguments
are, and why those arguments appear to be bad.

>>> Dan
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Received on 2014-04-02