[MPlayer-dev-eng] Mplayer 0.60pre1 drops privileges too early

[pl]

Hi,

In mplayer.c the line:

  setuid( getuid() ); // strongly test, please check this.

breaks svga/dga driver if suid bit is set on the binary as it is advised
in the FAQ for instance.

So either the FAQ is broken, either this code line has to be removed :)


On Wed, Dec 26, 2001 at 02:55:07AM +0100, ellen at euronet.nl wrote:

> I just compiled and installed Mplayer 0.60pre1, and set uid root,
> just like I did with 0.50, but when I run it as a normal user, it
> seems to forget or drop those privileges, no matter if I try to
> use SVGA or DGA:
> 
>      ==============================================================
> 
> ellen:/ftp/linux > mplayer-0.60pre1 -vo svga /win95/videos/747_takeoff.mpg
> 
> MPlayer 0.60pre1 (C) 2000-2001 Arpad Gereoffy (see DOCS!)
> 
> CPU vendor name: AuthenticAMD  max cpuid level: 1
> CPU: Advanced Micro Devices K6-2+/K6-III+ Sharptooth (Type: 5, Stepping: 0)
> extended cpuid-level: 7
> CPUflags: Type: 5 MMX: 1 MMX2: 0 3DNow: 1 3DNow2: 1 SSE: 0 SSE2: 0
> Reading /home/ellen/.mplayer/codecs.conf: 18 audio & 40 video codecs
> Font /home/ellen/.mplayer/font/font.desc loaded successfully! (102 chars)
> Using Linux's hardware RTC timing (1024Hz)

perms are dropped here

> Playing /win95/videos/747_takeoff.mpg
> Not an URL!
> header block 1 size: 0
> Detected MPEG-PS file format!
> VIDEO:  MPEG1  320x240  (aspect 1)  29.97 fps  1875.0 kbps (234.4 kbyte/s)
> [V] filefmt:2  fourcc:0x10000001  size:320x240  fps:29.97  ftime:=0.0334
> Detected audio codec: [mp3] drv:1 (MPEG layer-2, layer-3)
> mp3lib: Processor ID: 5d0
> mp3lib: Using AMD 3dnow-dsp(k7)! optimized decore.
> AUDIO: srate=44100  chans=2  bps=2  sfmt=0x10  ratio: 28000->176400
> Detected video codec: [mpeg12] drv:1 prio:0 (MPEG 1 or 2)
> svgalib: Cannot get I/O permissions.
> 
>      ==============================================================
> 
> ellen:/ftp/linux > mplayer-0.60pre1 -vo dga /win95/videos/747_takeoff.mpg
> 
> MPlayer 0.60pre1 (C) 2000-2001 Arpad Gereoffy (see DOCS!)
> 
> CPU vendor name: AuthenticAMD  max cpuid level: 1
> CPU: Advanced Micro Devices K6-2+/K6-III+ Sharptooth (Type: 5, Stepping: 0)
> extended cpuid-level: 7
> CPUflags: Type: 5 MMX: 1 MMX2: 0 3DNow: 1 3DNow2: 1 SSE: 0 SSE2: 0
> Reading /home/ellen/.mplayer/codecs.conf: 18 audio & 40 video codecs
> Font /home/ellen/.mplayer/font/font.desc loaded successfully! (102 chars)
> Using Linux's hardware RTC timing (1024Hz)
> Playing /win95/videos/747_takeoff.mpg
> Not an URL!
> header block 1 size: 0
> Detected MPEG-PS file format!
> VIDEO:  MPEG1  320x240  (aspect 1)  29.97 fps  1875.0 kbps (234.4 kbyte/s)
> [V] filefmt:2  fourcc:0x10000001  size:320x240  fps:29.97  ftime:=0.0334
> Detected audio codec: [mp3] drv:1 (MPEG layer-2, layer-3)
> mp3lib: Processor ID: 5d0
> mp3lib: Using AMD 3dnow-dsp(k7)! optimized decore.
> AUDIO: srate=44100  chans=2  bps=2  sfmt=0x10  ratio: 28000->176400
> Detected video codec: [mpeg12] drv:1 prio:0 (MPEG 1 or 2)
> vo: X11 running at 1152x864 with depth 16 and 16 bits/pixel (":0.0" => local display)
> vo_dga: Mode: depth=15, bpp=16, r=007c00, g=0003e0, b=00001f, conversion (slow), (-bpp 15) ...disabled by -bpp 16
> vo_dga: Mode: depth=16, bpp=16, r=00f800, g=0007e0, b=00001f, native (fast),     (-bpp 16)
> vo_dga: Mode: depth=24, bpp=24, r=ff0000, g=00ff00, b=0000ff, not supported :-(  (-bpp 24) ...disabled by -bpp 16
> vo_dga: Mode: depth=24, bpp=32, r=ff0000, g=00ff00, b=0000ff, not supported :-(  (-bpp 32) ...disabled by -bpp 16
> mpeg2dec-0.2.0-release (C) 2000-2001 Aaron Holtzman & Michel Lespinasse
> libmpeg2: Using MMX for IDCT transform
> libmpeg2: Using 3DNOW for motion compensation
> Movie-Aspect is undefined - no prescaling applied.
> VO: [dga] 320x240 => 320x240 Planar YV12 
> vo_dga: DGA 1.0 compatibility code: Using XF86VidMode for mode switching!
> vo_dga: XF86VidMode Extension v0.8
> vo_dga: Selected video mode  640 x  480 @  84 Hz @ depth 16, bitspp 16, video 320 x 240.
> XF86DGAGetVideo: failed to open /dev/mem (Permission denied)
> 
>      ==============================================================
> 
> Running both as root works fine, though, and running 0.50 as a normal
> users still works, too.  Permissions for the executables are:
> 
> -rwsr-sr-x   1 root     root       900916 Oct 25 20:59 mplayer-0.50
> -rwsr-sr-x   1 root     root      1100040 Dec 26 02:33 mplayer-0.60pre1
> 
> Running Slackware Linux 7.1,
> gcc version 2.95.2 19991024 (release)
--
pl