From: Wei Liu <[email protected]> Sent: Sunday, January 23, 2022 1:56 PM > > On Sun, Jan 16, 2022 at 09:53:06PM +0000, Haiyang Zhang wrote: > > > > > > > -----Original Message----- > > > From: Michael Kelley (LINUX) <[email protected]> > > > Sent: Sunday, January 16, 2022 2:19 PM > > > To: KY Srinivasan <[email protected]>; Haiyang Zhang > <[email protected]>; Stephen > > > Hemminger <[email protected]>; [email protected]; Wei Hu > <[email protected]>; Dexuan > > > Cui <[email protected]>; [email protected]; hhei <[email protected]>; > linux- > > > [email protected]; [email protected]; linux- > [email protected]; dri- > > > [email protected] > > > Cc: Michael Kelley (LINUX) <[email protected]> > > > Subject: [PATCH 1/1] video: hyperv_fb: Fix validation of screen resolution > > > > > > In the WIN10 version of the Synthetic Video protocol with Hyper-V, > > > Hyper-V reports a list of supported resolutions as part of the protocol > > > negotiation. The driver calculates the maximum width and height from > > > the list of resolutions, and uses those maximums to validate any screen > > > resolution specified in the video= option on the kernel boot line. > > > > > > This method of validation is incorrect. For example, the list of > > > supported resolutions could contain 1600x1200 and 1920x1080, both of > > > which fit in an 8 Mbyte frame buffer. But calculating the max width > > > and height yields 1920 and 1200, and 1920x1200 resolution does not fit > > > in an 8 Mbyte frame buffer. Unfortunately, this resolution is accepted, > > > causing a kernel fault when the driver accesses memory outside the > > > frame buffer. > > > > > > Instead, validate the specified screen resolution by calculating > > > its size, and comparing against the frame buffer size. Delete the > > > code for calculating the max width and height from the list of > > > resolutions, since these max values have no use. Also add the > > > frame buffer size to the info message to aid in understanding why > > > a resolution might be rejected. > > > > > > Fixes: 67e7cdb4829d ("video: hyperv: hyperv_fb: Obtain screen resolution > > > from Hyper-V > > > host") > > > Signed-off-by: Michael Kelley <[email protected]> > [...] > > > > Reviewed-by: Haiyang Zhang <[email protected]> > > > > Applied to hyperv-fixes. Thanks.
This fix got pulled into the fbdev/for-next tree by a new maintainer, Helge Deller. See https://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git/commit/?h=for-next&id=bcc48f8d980b12e66a3d59dfa1041667db971d86 Michael
