[FFmpeg-trac] #1940(avutil:new): segfault on av_malloc()

FFmpeg trac at avcodec.org
Wed Nov 21 15:36:58 CET 2012

#1940: segfault on av_malloc()
             Reporter:               |                     Type:  defect
  leandrosansilva                    |                 Priority:  critical
               Status:  new          |                  Version:  git-
            Component:  avutil       |  master
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
 I'm using ffmpeg in a c++ project and at a point at my code I try to call
 av_malloc() bu it results in a segfault. As I'm using ubuntu amd64 arch, I
 don't think I don't have enough memory. It's also strange it happens only
 in one point of my code, where I create a new pointer and just assign the
 return of av_malloc() (here the size is 460800) as parameter. It causes a
 segfault before return. It makes me think if libav keeps a internal state
 of general memory alocation system...

 The ffmpeg version I'm using is the commit
 e94f4294746d50ef7b25993fa59a9be32023d3bb checked out today (21th November)
 from master branch.

 The backtrace related to this problem is:

 Program received signal SIGSEGV, Segmentation fault.
 _int_malloc (av=0x7ffff6b63720, bytes=460880) at malloc.c:3868
 3868    malloc.c: Arquivo ou diretório não encontrado.
 (gdb) bt full
 #0  _int_malloc (av=0x7ffff6b63720, bytes=460880) at malloc.c:3868
         p = <optimized out>
         iters = <optimized out>
         nb = 460896
         idx = <optimized out>
         bin = <optimized out>
         victim = 0x1d6fae0
         size = 7740398493674188424
         victim_index = <optimized out>
         remainder = 0x1de0340
         remainder_size = <optimized out>
         block = 4
         bit = 1073741824
         map = <optimized out>
         fwd = <optimized out>
         bck = <optimized out>
         errstr = 0x0
         __func__ = "_int_malloc"
 #1  0x00007ffff682c801 in _int_memalign (av=0x7ffff6b63720, alignment=32,
 bytes=<optimized out>) at malloc.c:4492
         nb = 460816
         m = <optimized out>
         p = <optimized out>
         brk = <optimized out>
         newp = <optimized out>
         newsize = <optimized out>
         leadsize = <optimized out>
         remainder = <optimized out>
         remainder_size = <optimized out>
         size = <optimized out>
         __func__ = "_int_memalign"
 #2  0x00007ffff682eac6 in __GI___libc_memalign (alignment=32,
 bytes=460800) at malloc.c:3102
         ar_ptr = <optimized out>
         p = <optimized out>
         hook = <optimized out>
         __func__ = "__libc_memalign"
 #3  0x00007ffff682fd09 in __posix_memalign (memptr=0x7fffffffdc88,
 alignment=<optimized out>, size=<optimized out>) at malloc.c:5038
         mem = <optimized out>
         hook = <optimized out>
 #4  0x0000000000cfb22a in av_malloc (size=460800) at libavutil/mem.c:97
         ptr = 0x0
 #5  av_mallocz (size=460800) at libavutil/mem.c:203

 (...) my code bt (...)


Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1940>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker

More information about the FFmpeg-trac mailing list