linux-stable.git/drivers/video, branch v4.4.271 Linux kernel stable tree video: hgafb: correctly handle card detect failure during probe 2021-05-26T09:27:34+00:00 Anirudh Rayabharam mail@anirudhrb.com 2021-05-16T19:27:14+00:00 e7a48689d1e5ac2071baae98df356972d01dbf5e commit 02625c965239b71869326dd0461615f27307ecb3 upstream. The return value of hga_card_detect() is not properly handled causing the probe to succeed even though hga_card_detect() failed. Since probe succeeds, hgafb_open() can be called which will end up operating on an unmapped hga_vram. This results in an out-of-bounds access as reported by kernel test robot [1]. To fix this, correctly detect failure of hga_card_detect() by checking for a non-zero error code. [1]: https://lore.kernel.org/lkml/20210516150019.GB25903@xsang-OptiPlex-9020/ Fixes: dc13cac4862c ("video: hgafb: fix potential NULL pointer dereference") Cc: stable <stable@vger.kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Reviewed-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com> Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20210516192714.25823-1-mail@anirudhrb.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 02625c965239b71869326dd0461615f27307ecb3 upstream.

The return value of hga_card_detect() is not properly handled causing
the probe to succeed even though hga_card_detect() failed. Since probe
succeeds, hgafb_open() can be called which will end up operating on an
unmapped hga_vram. This results in an out-of-bounds access as reported
by kernel test robot [1].

To fix this, correctly detect failure of hga_card_detect() by checking
for a non-zero error code.

[1]: https://lore.kernel.org/lkml/20210516150019.GB25903@xsang-OptiPlex-9020/

Fixes: dc13cac4862c ("video: hgafb: fix potential NULL pointer dereference")
Cc: stable <stable@vger.kernel.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20210516192714.25823-1-mail@anirudhrb.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: vt: always invoke vc->vc_sw->con_resize callback 2021-05-26T09:27:34+00:00 Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp 2021-05-15T03:00:37+00:00 e6c40c7df14497169e00e1e776c4cdb19d7d6bc0 commit ffb324e6f874121f7dce5bdae5e05d02baae7269 upstream. syzbot is reporting OOB write at vga16fb_imageblit() [1], for resize_screen() from ioctl(VT_RESIZE) returns 0 without checking whether requested rows/columns fit the amount of memory reserved for the graphical screen if current mode is KD_GRAPHICS. ---------- #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/kd.h> #include <linux/vt.h> int main(int argc, char *argv[]) { const int fd = open("/dev/char/4:1", O_RDWR); struct vt_sizes vt = { 0x4100, 2 }; ioctl(fd, KDSETMODE, KD_GRAPHICS); ioctl(fd, VT_RESIZE, &vt); ioctl(fd, KDSETMODE, KD_TEXT); return 0; } ---------- Allow framebuffer drivers to return -EINVAL, by moving vc->vc_mode != KD_GRAPHICS check from resize_screen() to fbcon_resize(). Link: https://syzkaller.appspot.com/bug?extid=1f29e126cf461c4de3b3 [1] Reported-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ffb324e6f874121f7dce5bdae5e05d02baae7269 upstream.

syzbot is reporting OOB write at vga16fb_imageblit() [1], for
resize_screen() from ioctl(VT_RESIZE) returns 0 without checking whether
requested rows/columns fit the amount of memory reserved for the graphical
screen if current mode is KD_GRAPHICS.

----------
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <sys/ioctl.h>
  #include <linux/kd.h>
  #include <linux/vt.h>

  int main(int argc, char *argv[])
  {
        const int fd = open("/dev/char/4:1", O_RDWR);
        struct vt_sizes vt = { 0x4100, 2 };

        ioctl(fd, KDSETMODE, KD_GRAPHICS);
        ioctl(fd, VT_RESIZE, &vt);
        ioctl(fd, KDSETMODE, KD_TEXT);
        return 0;
  }
----------

Allow framebuffer drivers to return -EINVAL, by moving vc->vc_mode !=
KD_GRAPHICS check from resize_screen() to fbcon_resize().

Link: https://syzkaller.appspot.com/bug?extid=1f29e126cf461c4de3b3 [1]
Reported-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: Fix character height handling with VT_RESIZEX 2021-05-26T09:27:34+00:00 Maciej W. Rozycki macro@orcam.me.uk 2021-05-13T09:51:50+00:00 cf4cdc59a1e401cdc01944488d88068aafda8f8d commit 860dafa902595fb5f1d23bbcce1215188c3341e6 upstream. Restore the original intent of the VT_RESIZEX ioctl's `v_clin' parameter which is the number of pixel rows per character (cell) rather than the height of the font used. For framebuffer devices the two values are always the same, because the former is inferred from the latter one. For VGA used as a true text mode device these two parameters are independent from each other: the number of pixel rows per character is set in the CRT controller, while font height is in fact hardwired to 32 pixel rows and fonts of heights below that value are handled by padding their data with blanks when loaded to hardware for use by the character generator. One can change the setting in the CRT controller and it will update the screen contents accordingly regardless of the font loaded. The `v_clin' parameter is used by the `vgacon' driver to set the height of the character cell and then the cursor position within. Make the parameter explicit then, by defining a new `vc_cell_height' struct member of `vc_data', set it instead of `vc_font.height' from `v_clin' in the VT_RESIZEX ioctl, and then use it throughout the `vgacon' driver except where actual font data is accessed which as noted above is independent from the CRTC setting. This way the framebuffer console driver is free to ignore the `v_clin' parameter as irrelevant, as it always should have, avoiding any issues attempts to give the parameter a meaning there could have caused, such as one that has led to commit 988d0763361b ("vt_ioctl: make VT_RESIZEX behave like VT_RESIZE"): "syzbot is reporting UAF/OOB read at bit_putcs()/soft_cursor() [1][2], for vt_resizex() from ioctl(VT_RESIZEX) allows setting font height larger than actual font height calculated by con_font_set() from ioctl(PIO_FONT). Since fbcon_set_font() from con_font_set() allocates minimal amount of memory based on actual font height calculated by con_font_set(), use of vt_resizex() can cause UAF/OOB read for font data." The problem first appeared around Linux 2.5.66 which predates our repo history, but the origin could be identified with the old MIPS/Linux repo also at: <git://git.kernel.org/pub/scm/linux/kernel/git/ralf/linux.git> as commit 9736a3546de7 ("Merge with Linux 2.5.66."), where VT_RESIZEX code in `vt_ioctl' was updated as follows: if (clin) - video_font_height = clin; + vc->vc_font.height = clin; making the parameter apply to framebuffer devices as well, perhaps due to the use of "font" in the name of the original `video_font_height' variable. Use "cell" in the new struct member then to avoid ambiguity. References: [1] https://syzkaller.appspot.com/bug?id=32577e96d88447ded2d3b76d71254fb855245837 [2] https://syzkaller.appspot.com/bug?id=6b8355d27b2b94fb5cedf4655e3a59162d9e48e3 Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org # v2.6.12+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 860dafa902595fb5f1d23bbcce1215188c3341e6 upstream.

Restore the original intent of the VT_RESIZEX ioctl's `v_clin' parameter
which is the number of pixel rows per character (cell) rather than the
height of the font used.

For framebuffer devices the two values are always the same, because the
former is inferred from the latter one.  For VGA used as a true text
mode device these two parameters are independent from each other: the
number of pixel rows per character is set in the CRT controller, while
font height is in fact hardwired to 32 pixel rows and fonts of heights
below that value are handled by padding their data with blanks when
loaded to hardware for use by the character generator.  One can change
the setting in the CRT controller and it will update the screen contents
accordingly regardless of the font loaded.

The `v_clin' parameter is used by the `vgacon' driver to set the height
of the character cell and then the cursor position within.  Make the
parameter explicit then, by defining a new `vc_cell_height' struct
member of `vc_data', set it instead of `vc_font.height' from `v_clin' in
the VT_RESIZEX ioctl, and then use it throughout the `vgacon' driver
except where actual font data is accessed which as noted above is
independent from the CRTC setting.

This way the framebuffer console driver is free to ignore the `v_clin'
parameter as irrelevant, as it always should have, avoiding any issues
attempts to give the parameter a meaning there could have caused, such
as one that has led to commit 988d0763361b ("vt_ioctl: make VT_RESIZEX
behave like VT_RESIZE"):

 "syzbot is reporting UAF/OOB read at bit_putcs()/soft_cursor() [1][2],
  for vt_resizex() from ioctl(VT_RESIZEX) allows setting font height
  larger than actual font height calculated by con_font_set() from
  ioctl(PIO_FONT). Since fbcon_set_font() from con_font_set() allocates
  minimal amount of memory based on actual font height calculated by
  con_font_set(), use of vt_resizex() can cause UAF/OOB read for font
  data."

The problem first appeared around Linux 2.5.66 which predates our repo
history, but the origin could be identified with the old MIPS/Linux repo
also at: <git://git.kernel.org/pub/scm/linux/kernel/git/ralf/linux.git>
as commit 9736a3546de7 ("Merge with Linux 2.5.66."), where VT_RESIZEX
code in `vt_ioctl' was updated as follows:

 		if (clin)
-			video_font_height = clin;
+			vc->vc_font.height = clin;

making the parameter apply to framebuffer devices as well, perhaps due
to the use of "font" in the name of the original `video_font_height'
variable.  Use "cell" in the new struct member then to avoid ambiguity.

References:

[1] https://syzkaller.appspot.com/bug?id=32577e96d88447ded2d3b76d71254fb855245837
[2] https://syzkaller.appspot.com/bug?id=6b8355d27b2b94fb5cedf4655e3a59162d9e48e3

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org # v2.6.12+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vgacon: Record video mode changes with VT_RESIZEX 2021-05-26T09:27:33+00:00 Maciej W. Rozycki macro@orcam.me.uk 2021-05-13T09:51:41+00:00 aedb540597f61c618394d04ce53ea625d03c8bde commit d4d0ad57b3865795c4cde2fb5094c594c2e8f469 upstream. Fix an issue with VGA console font size changes made after the initial video text mode has been changed with a user tool like `svgatextmode' calling the VT_RESIZEX ioctl. As it stands in that case the original screen geometry continues being used to validate further VT resizing. Consequently when the video adapter is firstly reprogrammed from the original say 80x25 text mode using a 9x16 character cell (720x400 pixel resolution) to say 80x37 text mode and the same character cell (720x592 pixel resolution), and secondly the CRTC character cell updated to 9x8 (by loading a suitable font with the KD_FONT_OP_SET request of the KDFONTOP ioctl), the VT geometry does not get further updated from 80x37 and only upper half of the screen is used for the VT, with the lower half showing rubbish corresponding to whatever happens to be there in the video memory that maps to that part of the screen. Of course the proportions change according to text mode geometries and font sizes chosen. Address the problem then, by updating the text mode geometry defaults rather than checking against them whenever the VT is resized via a user ioctl. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: e400b6ec4ede ("vt/vgacon: Check if screen resize request comes from userspace") Cc: stable@vger.kernel.org # v2.6.24+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d4d0ad57b3865795c4cde2fb5094c594c2e8f469 upstream.

Fix an issue with VGA console font size changes made after the initial
video text mode has been changed with a user tool like `svgatextmode'
calling the VT_RESIZEX ioctl.  As it stands in that case the original
screen geometry continues being used to validate further VT resizing.

Consequently when the video adapter is firstly reprogrammed from the
original say 80x25 text mode using a 9x16 character cell (720x400 pixel
resolution) to say 80x37 text mode and the same character cell (720x592
pixel resolution), and secondly the CRTC character cell updated to 9x8
(by loading a suitable font with the KD_FONT_OP_SET request of the
KDFONTOP ioctl), the VT geometry does not get further updated from 80x37
and only upper half of the screen is used for the VT, with the lower
half showing rubbish corresponding to whatever happens to be there in
the video memory that maps to that part of the screen.  Of course the
proportions change according to text mode geometries and font sizes
chosen.

Address the problem then, by updating the text mode geometry defaults
rather than checking against them whenever the VT is resized via a user
ioctl.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: e400b6ec4ede ("vt/vgacon: Check if screen resize request comes from userspace")
Cc: stable@vger.kernel.org # v2.6.24+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
video: hgafb: fix potential NULL pointer dereference 2021-05-26T09:27:33+00:00 Igor Matheus Andrade Torrente igormtorrente@gmail.com 2021-05-03T11:57:06+00:00 1b7184e227995cf14126722f4db8995edb8e13f3 commit dc13cac4862cc68ec74348a80b6942532b7735fa upstream. The return of ioremap if not checked, and can lead to a NULL to be assigned to hga_vram. Potentially leading to a NULL pointer dereference. The fix adds code to deal with this case in the error label and changes how the hgafb_probe handles the return of hga_card_detect. Cc: Ferenc Bakonyi <fero@drama.obuda.kando.hu> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com> Link: https://lore.kernel.org/r/20210503115736.2104747-40-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit dc13cac4862cc68ec74348a80b6942532b7735fa upstream.

The return of ioremap if not checked, and can lead to a NULL to be
assigned to hga_vram. Potentially leading to a NULL pointer
dereference.

The fix adds code to deal with this case in the error label and
changes how the hgafb_probe handles the return of hga_card_detect.

Cc: Ferenc Bakonyi <fero@drama.obuda.kando.hu>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
Link: https://lore.kernel.org/r/20210503115736.2104747-40-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "video: imsttfb: fix potential NULL pointer dereferences" 2021-05-26T09:27:32+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2021-05-03T11:57:33+00:00 4161f37dc39c25fc467ccb26a4ddfeabef72ee32 commit ed04fe8a0e87d7b5ea17d47f4ac9ec962b24814a upstream. This reverts commit 1d84353d205a953e2381044953b7fa31c8c9702d. Because of recent interactions with developers from @umn.edu, all commits from them have been recently re-reviewed to ensure if they were correct or not. Upon review, this commit was found to be incorrect for the reasons below, so it must be reverted. It will be fixed up "correctly" in a later kernel change. The original commit here, while technically correct, did not fully handle all of the reported issues that the commit stated it was fixing, so revert it until it can be "fixed" fully. Note, ioremap() probably will never fail for old hardware like this, and if anyone actually used this hardware (a PowerMac era PCI display card), they would not be using fbdev anymore. Cc: Kangjie Lu <kjlu@umn.edu> Cc: Aditya Pakki <pakki001@umn.edu> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Reviewed-by: Rob Herring <robh@kernel.org> Fixes: 1d84353d205a ("video: imsttfb: fix potential NULL pointer dereferences") Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210503115736.2104747-67-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ed04fe8a0e87d7b5ea17d47f4ac9ec962b24814a upstream.

This reverts commit 1d84353d205a953e2381044953b7fa31c8c9702d.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

The original commit here, while technically correct, did not fully
handle all of the reported issues that the commit stated it was fixing,
so revert it until it can be "fixed" fully.

Note, ioremap() probably will never fail for old hardware like this, and
if anyone actually used this hardware (a PowerMac era PCI display card),
they would not be using fbdev anymore.

Cc: Kangjie Lu <kjlu@umn.edu>
Cc: Aditya Pakki <pakki001@umn.edu>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Fixes: 1d84353d205a ("video: imsttfb: fix potential NULL pointer dereferences")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-67-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "video: hgafb: fix potential NULL pointer dereference" 2021-05-26T09:27:32+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2021-05-03T11:57:05+00:00 0596375e92813822b700014207ff585bba3451a2 commit 58c0cc2d90f1e37c4eb63ae7f164c83830833f78 upstream. This reverts commit ec7f6aad57ad29e4e66cc2e18e1e1599ddb02542. Because of recent interactions with developers from @umn.edu, all commits from them have been recently re-reviewed to ensure if they were correct or not. Upon review, this commit was found to be incorrect for the reasons below, so it must be reverted. It will be fixed up "correctly" in a later kernel change. This patch "looks" correct, but the driver keeps on running and will fail horribly right afterward if this error condition ever trips. So points for trying to resolve an issue, but a huge NEGATIVE value for providing a "fake" fix for the problem as nothing actually got resolved at all. I'll go fix this up properly... Cc: Kangjie Lu <kjlu@umn.edu> Cc: Aditya Pakki <pakki001@umn.edu> Cc: Ferenc Bakonyi <fero@drama.obuda.kando.hu> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Fixes: ec7f6aad57ad ("video: hgafb: fix potential NULL pointer dereference") Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210503115736.2104747-39-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 58c0cc2d90f1e37c4eb63ae7f164c83830833f78 upstream.

This reverts commit ec7f6aad57ad29e4e66cc2e18e1e1599ddb02542.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

This patch "looks" correct, but the driver keeps on running and will
fail horribly right afterward if this error condition ever trips.

So points for trying to resolve an issue, but a huge NEGATIVE value for
providing a "fake" fix for the problem as nothing actually got resolved
at all.  I'll go fix this up properly...

Cc: Kangjie Lu <kjlu@umn.edu>
Cc: Aditya Pakki <pakki001@umn.edu>
Cc: Ferenc Bakonyi <fero@drama.obuda.kando.hu>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Fixes: ec7f6aad57ad ("video: hgafb: fix potential NULL pointer dereference")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-39-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fbdev: zero-fill colormap in fbcmap.c 2021-05-22T08:38:17+00:00 Phillip Potter phil@philpotter.co.uk 2021-03-31T22:07:19+00:00 92194685fd958bca26578518465b4a5cc159be80 commit 19ab233989d0f7ab1de19a036e247afa4a0a1e9c upstream. Use kzalloc() rather than kmalloc() for the dynamically allocated parts of the colormap in fb_alloc_cmap_gfp, to prevent a leak of random kernel data to userspace under certain circumstances. Fixes a KMSAN-found infoleak bug reported by syzbot at: https://syzkaller.appspot.com/bug?id=741578659feabd108ad9e06696f0c1f2e69c4b6e Reported-by: syzbot+47fa9c9c648b765305b9@syzkaller.appspotmail.com Cc: stable <stable@vger.kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Phillip Potter <phil@philpotter.co.uk> Link: https://lore.kernel.org/r/20210331220719.1499743-1-phil@philpotter.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 19ab233989d0f7ab1de19a036e247afa4a0a1e9c upstream.

Use kzalloc() rather than kmalloc() for the dynamically allocated parts
of the colormap in fb_alloc_cmap_gfp, to prevent a leak of random kernel
data to userspace under certain circumstances.

Fixes a KMSAN-found infoleak bug reported by syzbot at:
https://syzkaller.appspot.com/bug?id=741578659feabd108ad9e06696f0c1f2e69c4b6e

Reported-by: syzbot+47fa9c9c648b765305b9@syzkaller.appspotmail.com
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210331220719.1499743-1-phil@philpotter.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fbdev: aty: SPARC64 requires FB_ATY_CT 2021-03-03T15:44:16+00:00 Randy Dunlap rdunlap@infradead.org 2020-11-27T03:17:52+00:00 695c5332855fcdb7d4bffa39b7b4670435f336e9 [ Upstream commit c6c90c70db4d9a0989111d6b994d545659410f7a ] It looks like SPARC64 requires FB_ATY_CT to build without errors, so have FB_ATY select FB_ATY_CT if both SPARC64 and PCI are enabled instead of using "default y if SPARC64 && PCI", which is not strong enough to prevent build errors. As it currently is, FB_ATY_CT can be disabled, resulting in build errors: ERROR: modpost: "aty_postdividers" [drivers/video/fbdev/aty/atyfb.ko] undefined! ERROR: modpost: "aty_ld_pll_ct" [drivers/video/fbdev/aty/atyfb.ko] undefined! Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Fixes: f7018c213502 ("video: move fbdev to drivers/video/fbdev") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: sparclinux@vger.kernel.org Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20201127031752.10371-1-rdunlap@infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c6c90c70db4d9a0989111d6b994d545659410f7a ]

It looks like SPARC64 requires FB_ATY_CT to build without errors,
so have FB_ATY select FB_ATY_CT if both SPARC64 and PCI are enabled
instead of using "default y if SPARC64 && PCI", which is not strong
enough to prevent build errors.

As it currently is, FB_ATY_CT can be disabled, resulting in build
errors:

ERROR: modpost: "aty_postdividers" [drivers/video/fbdev/aty/atyfb.ko] undefined!
ERROR: modpost: "aty_ld_pll_ct" [drivers/video/fbdev/aty/atyfb.ko] undefined!

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Fixes: f7018c213502 ("video: move fbdev to drivers/video/fbdev")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127031752.10371-1-rdunlap@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
video: hyperv_fb: Fix the mmap() regression for v5.4.y and older 2021-01-12T18:47:55+00:00 Dexuan Cui decui@microsoft.com 2021-01-09T22:53:58+00:00 452f087d2ff6decf298149e0bfd9fa5c212a636d db49200b1dad is backported from the mainline commit 5f1251a48c17 ("video: hyperv_fb: Fix the cache type when mapping the VRAM"), to v5.4.y and older stable branches, but unluckily db49200b1dad causes mmap() to fail for /dev/fb0 due to EINVAL: [ 5797.049560] x86/PAT: a.out:1910 map pfn expected mapping type uncached-minus for [mem 0xf8200000-0xf85cbfff], got write-back This means the v5.4.y kernel detects an incompatibility issue about the mapping type of the VRAM: db49200b1dad changes to use Write-Back when mapping the VRAM, while the mmap() syscall tries to use Uncached-minus. That’s to say, the kernel thinks Uncached-minus is incompatible with Write-Back: see drivers/video/fbdev/core/fbmem.c: fb_mmap() -> vm_iomap_memory() -> io_remap_pfn_range() -> ... -> track_pfn_remap() -> reserve_pfn_range(). Note: any v5.5 and newer kernel doesn't have the issue, because they have commit d21987d709e8 ("video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver") , and when the hyperv_fb driver has the deferred_io support, fb_deferred_io_init() overrides info->fbops->fb_mmap with fb_deferred_io_mmap(), which doesn’t check the mapping type incompatibility. Note: since it's VRAM here, the checking is not really necessary. Fix the regression by ioremap_wc(), which uses Write-combining. The kernel thinks it's compatible with Uncached-minus. The VRAM mappped by ioremap_wc() is slightly slower than mapped by ioremap_cache(), but is still significantly faster than by ioremap(). Change the comment accordingly. Linux VM on ARM64 Hyper-V is still not working in the latest mainline yet, and when it works in future, the ARM64 support is unlikely to be backported to v5.4 and older, so using ioremap_wc() in v5.4 and older should be ok. Note: this fix is only targeted at the stable branches: v5.4.y, v4.19.y, v4.14.y, v4.9.y and v4.4.y. Fixes: db49200b1dad ("video: hyperv_fb: Fix the cache type when mapping the VRAM") Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
db49200b1dad is backported from the mainline commit
5f1251a48c17 ("video: hyperv_fb: Fix the cache type when mapping the VRAM"),
to v5.4.y and older stable branches, but unluckily db49200b1dad causes
mmap() to fail for /dev/fb0 due to EINVAL:

[ 5797.049560] x86/PAT: a.out:1910 map pfn expected mapping type
  uncached-minus for [mem 0xf8200000-0xf85cbfff], got write-back

This means the v5.4.y kernel detects an incompatibility issue about the
mapping type of the VRAM: db49200b1dad changes to use Write-Back when
mapping the VRAM, while the mmap() syscall tries to use Uncached-minus.
That’s to say, the kernel thinks Uncached-minus is incompatible with
Write-Back: see drivers/video/fbdev/core/fbmem.c: fb_mmap() ->
vm_iomap_memory() -> io_remap_pfn_range() -> ... -> track_pfn_remap() ->
reserve_pfn_range().

Note: any v5.5 and newer kernel doesn't have the issue, because they
have commit
d21987d709e8 ("video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver")
, and when the hyperv_fb driver has the deferred_io support,
fb_deferred_io_init() overrides info->fbops->fb_mmap with
fb_deferred_io_mmap(), which doesn’t check the mapping type
incompatibility. Note: since it's VRAM here, the checking is not really
necessary.

Fix the regression by ioremap_wc(), which uses Write-combining. The kernel
thinks it's compatible with Uncached-minus. The VRAM mappped by
ioremap_wc() is slightly slower than mapped by ioremap_cache(), but is
still significantly faster than by ioremap().

Change the comment accordingly. Linux VM on ARM64 Hyper-V is still not
working in the latest mainline yet, and when it works in future, the ARM64
support is unlikely to be backported to v5.4 and older, so using
ioremap_wc() in v5.4 and older should be ok.

Note: this fix is only targeted at the stable branches:
v5.4.y, v4.19.y, v4.14.y, v4.9.y and v4.4.y.

Fixes: db49200b1dad ("video: hyperv_fb: Fix the cache type when mapping the VRAM")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>