| Message ID | 20200427091945.57534-1-christophe.jaillet@wanadoo.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | video: fbdev: w100fb: Fix a potential double free. | expand |
Hi Christophe On Mon, Apr 27, 2020 at 11:19:45AM +0200, Christophe JAILLET wrote: > Some memory is vmalloc'ed in the 'suspend' function and freed in the > 'resume' function. > However, it is also freed in the remove function. > > In order to avoid a potential double free, set the corresponding pointer > to NULL once freed in the 'resume' function. The changelog talks about a suspend and a resume function. But the code has a w100fb_save_vidmem() and a w100fb_restore_vidmem() functions. > > Fixes: aac51f09d96a ("[PATCH] w100fb: Rewrite for platform independence") This "Fixes" should be followed by: Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Antonino Daplas <adaplas@pol.net> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: <stable@vger.kernel.org> # v2.6.14+ This is the output of "dim fixes" - that does some magic to provide the above list. I filtered a few candidates out that should not be there. Please fix both issues and resend. Thanks, Sam > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > --- > drivers/video/fbdev/w100fb.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/video/fbdev/w100fb.c b/drivers/video/fbdev/w100fb.c > index 2d6e2738b792..d96ab28f8ce4 100644 > --- a/drivers/video/fbdev/w100fb.c > +++ b/drivers/video/fbdev/w100fb.c > @@ -588,6 +588,7 @@ static void w100fb_restore_vidmem(struct w100fb_par *par) > memsize=par->mach->mem->size; > memcpy_toio(remapped_fbuf + (W100_FB_BASE-MEM_WINDOW_BASE), par->saved_extmem, memsize); > vfree(par->saved_extmem); > + par->saved_extmem = NULL; > } > if (par->saved_intmem) { > memsize=MEM_INT_SIZE; > @@ -596,6 +597,7 @@ static void w100fb_restore_vidmem(struct w100fb_par *par) > else > memcpy_toio(remapped_fbuf + (W100_FB_BASE-MEM_WINDOW_BASE), par->saved_intmem, memsize); > vfree(par->saved_intmem); > + par->saved_intmem = NULL; > } > } > > -- > 2.25.1 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/video/fbdev/w100fb.c b/drivers/video/fbdev/w100fb.c index 2d6e2738b792..d96ab28f8ce4 100644 --- a/drivers/video/fbdev/w100fb.c +++ b/drivers/video/fbdev/w100fb.c @@ -588,6 +588,7 @@ static void w100fb_restore_vidmem(struct w100fb_par *par) memsize=par->mach->mem->size; memcpy_toio(remapped_fbuf + (W100_FB_BASE-MEM_WINDOW_BASE), par->saved_extmem, memsize); vfree(par->saved_extmem); + par->saved_extmem = NULL; } if (par->saved_intmem) { memsize=MEM_INT_SIZE; @@ -596,6 +597,7 @@ static void w100fb_restore_vidmem(struct w100fb_par *par) else memcpy_toio(remapped_fbuf + (W100_FB_BASE-MEM_WINDOW_BASE), par->saved_intmem, memsize); vfree(par->saved_intmem); + par->saved_intmem = NULL; } }
Some memory is vmalloc'ed in the 'suspend' function and freed in the 'resume' function. However, it is also freed in the remove function. In order to avoid a potential double free, set the corresponding pointer to NULL once freed in the 'resume' function. Fixes: aac51f09d96a ("[PATCH] w100fb: Rewrite for platform independence") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- drivers/video/fbdev/w100fb.c | 2 ++ 1 file changed, 2 insertions(+)