Comment 28 for bug 98783

A few lines from strace may be of interest, though strace bombs out pretty early.
It suggests okular is using the MIT-SHM extension for something, though if that were the problem the memory would show up in ipcs and would show up as shared memory in top. I think the problem is in server side allocated "shared" memory

strace okular /tmp/n2798.pdf 2>&1 | egrep -i "shm|pixmap" | fgrep -v ENOENT
writev(7, [{"b\0\4\0\7\0\0\0"..., 8}, {"MIT-SHM"..., 7}, {"\0"..., 1}], 3) = 16
writev(7, [{"b\0\4\0\7\0\0\0"..., 8}, {"MIT-SHM"..., 7}, {"\0"..., 1}], 3) = 16
writev(16, [{"b\0\4\0\7\0\0\4"..., 8}, {"MIT-SHM"..., 7}, {"\0"..., 1}], 3) = 16
read(19, "KDE PIXMAP CACHE DEUX\177\0\0\10\2\0\0\177r\26\0\0"..., 4096) = 4096
read(19, "KDE PIXMAP CACHE DEUX\177\0\0\10\2\0\0f\274\1\0R"..., 4096) = 4096
read(19, "KDE PIXMAP CACHE DEUX\177\0\0\10\2\0\0\177r\26\0\0"..., 4096) = 4096
read(19, "KDE PIXMAP CACHE DEUX\177\0\0\10\2\0\0f\274\1\0R"..., 4096) = 4096
lstat("/usr/share/pixmaps", {st_mode=S_IFDIR|0755, st_size=32768, ...}) = 0
stat("/usr/share/pixmaps", {st_mode=S_IFDIR|0755, st_size=32768, ...}) = 0
read(19, "KDE PIXMAP CACHE DEUX\177\0\0\10\2\0\0\177r\26\0\0"..., 4096) = 4096
read(19, "KDE PIXMAP CACHE DEUX\177\0\0\10\2\0\0f\274\1\0R"..., 4096) = 4096
read(19, "KDE PIXMAP CACHE DEUX\177\0\0\10\2\0\0\177r\26\0\0"..., 4096) = 4096
read(19, "KDE PIXMAP CACHE DEUX\177\0\0\10\2\0\0f\274\1\0R"..., 4096) = 4096
*** glibc detected *** strace: malloc(): memory corruption (fast): 0x0000000000f6f610 ***
======= Backtrace: =========
/lib/libc.so.6[0x7f3c20dc5cb8]
/lib/libc.so.6[0x7f3c20dc9351]
/lib/libc.so.6(__libc_malloc+0x98)[0x7f3c20dca828]
strace[0x4087d8]
strace[0x405c0e]
strace[0x404916]
/lib/libc.so.6(__libc_start_main+0xe6)[0x7f3c20d6c5a6]
strace[0x402119]