From ad6f93e9cd56f0b10e9b22e3e137d17a1a035242 Mon Sep 17 00:00:00 2001 From: Tom Rix Date: Wed, 5 Aug 2020 07:52:08 -0700 Subject: video: fbdev: sis: fix null ptr dereference 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: 544393fe584d ("[PATCH] sisfb update") Signed-off-by: Tom Rix Cc: Thomas Winischhofer Cc: Andrew Morton Signed-off-by: Bartlomiej Zolnierkiewicz Link: https://patchwork.freedesktop.org/patch/msgid/20200805145208.17727-1-trix@redhat.com --- drivers/video/fbdev/sis/init.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'drivers') diff --git a/drivers/video/fbdev/sis/init.c b/drivers/video/fbdev/sis/init.c index dfe3eb769638..fde27feae5d0 100644 --- a/drivers/video/fbdev/sis/init.c +++ b/drivers/video/fbdev/sis/init.c @@ -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; -- cgit v1.2.3-59-g8ed1b