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video: fbdev: sis: fix null ptr dereference

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Clang static analysis reports this representative error

init.c:2501:18: warning: Array access (from variable 'queuedata') results
  in a null pointer dereference
      templ |= ((queuedata[i] & 0xc0) << 3);

This is the problem block of code

   if(ModeNo > 0x13) {
      ...
      if(SiS_Pr->ChipType == SIS_730) {
	 queuedata = &FQBQData730[0];
      } else {
	 queuedata = &FQBQData[0];
      }
   } else {

   }

queuedata is not set in the else block

Reviewing the old code, the arrays FQBQData730 and FQBQData were
used directly.

So hoist the setting of queuedata out of the if-else block.

Fixes: 544393fe58 ("[PATCH] sisfb update")
Signed-off-by: Tom Rix <trix@redhat.com>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200805145208.17727-1-trix@redhat.com
This commit is contained in:
Tom Rix 2020-08-05 07:52:08 -07:00 committed by Bartlomiej Zolnierkiewicz
parent fe2ab10753
commit ad6f93e9cd
1 changed files with 5 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
drivers/video/fbdev/sis/init.c
View File

@ -2428,6 +2428,11 @@ SiS_SetCRT1FIFO_630(struct SiS_Private *SiS_Pr, unsigned short ModeNo,
i = 0;
if (SiS_Pr->ChipType == SIS_730)
queuedata = &FQBQData730[0];
else
queuedata = &FQBQData[0];
if(ModeNo > 0x13) {
/* Get VCLK */
@ -2445,12 +2450,6 @@ SiS_SetCRT1FIFO_630(struct SiS_Private *SiS_Pr, unsigned short ModeNo,
/* Get half colordepth */
colorth = colortharray[(SiS_Pr->SiS_ModeType - ModeEGA)];
if(SiS_Pr->ChipType == SIS_730) {
queuedata = &FQBQData730[0];
} else {
queuedata = &FQBQData[0];
}
do {
templ = SiS_CalcDelay2(SiS_Pr, queuedata[i]) * VCLK * colorth;