linux-stable.git/drivers/video/fbdev, branch v5.13.4

fbmem: Do not delete the mode that is still in use

2021-07-20T14:00:10+00:00

commit 0af778269a522c988ef0b4188556aba97fb420cc upstream.

The execution of fb_delete_videomode() is not based on the result of the
previous fbcon_mode_deleted(). As a result, the mode is directly deleted,
regardless of whether it is still in use, which may cause UAF.

==================================================================
BUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \
drivers/video/fbdev/core/modedb.c:924
Read of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962

CPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ...
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x137/0x1be lib/dump_stack.c:118
 print_address_description+0x6c/0x640 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report+0x13d/0x1e0 mm/kasan/report.c:562
 fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924
 fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746
 fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975
 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 18960:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track+0x3d/0x70 mm/kasan/common.c:56
 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422
 slab_free_hook mm/slub.c:1541 [inline]
 slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574
 slab_free mm/slub.c:3139 [inline]
 kfree+0xca/0x3d0 mm/slub.c:4121
 fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104
 fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978
 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 13ff178ccd6d ("fbcon: Call fbcon_mode_deleted/new_modelist directly")
Signed-off-by: Zhen Lei 
Cc:  # v5.3+
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20210712085544.2828-1-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman

video: fbdev: imxfb: Fix an error message

2021-07-14T15:06:55+00:00

[ Upstream commit 767d724a160eb1cd00c86fb8c2e21fa1ab3c37ac ]

'ret' is known to be 0 here.
No error code is available, so just remove it from the error message.

Fixes: 72330b0eeefc ("i.MX Framebuffer: Use readl/writel instead of direct pointer deref")
Reviewed-by: Uwe Kleine-König 
Signed-off-by: Christophe JAILLET 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/d7b25026f82659da3c6f7159eea480faa9d738be.1620327302.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Sasha Levin

Revert "fb_defio: Remove custom address_space_operations"

2021-06-01T15:38:40+00:00

Commit ccf953d8f3d6 makes framebuffers which use deferred I/O stop
displaying updates after the first one.  This is because the pages
handled by fb_defio no longer have a page_mapping().  That prevents
page_mkclean() from marking the PTEs as clean, and so writes are only
noticed the first time.

Reported-by: Andy Shevchenko 
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/YLZEhv0cpZp8uVE3@casper.infradead.org

video: hgafb: correctly handle card detect failure during probe

2021-05-21T13:04:05+00:00

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 
Reported-by: kernel test robot 
Reviewed-by: Igor Matheus Andrade Torrente 
Signed-off-by: Anirudh Rayabharam 
Signed-off-by: Dan Carpenter 
Link: https://lore.kernel.org/r/20210516192714.25823-1-mail@anirudhrb.com
Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2021-05-20T16:31:52+00:00

Pull char/misc driver fixes from Greg KH:
 "Here is a big set of char/misc/other driver fixes for 5.13-rc3.

  The majority here is the fallout of the umn.edu re-review of all prior
  submissions. That resulted in a bunch of reverts along with the
  "correct" changes made, such that there is no regression of any of the
  potential fixes that were made by those individuals. I would like to
  thank the over 80 different developers who helped with the review and
  fixes for this mess.

  Other than that, there's a few habanna driver fixes for reported
  issues, and some dyndbg fixes for reported problems.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'char-misc-5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (82 commits)
  misc: eeprom: at24: check suspend status before disable regulator
  uio_hv_generic: Fix another memory leak in error handling paths
  uio_hv_generic: Fix a memory leak in error handling paths
  uio/uio_pci_generic: fix return value changed in refactoring
  Revert "Revert "ALSA: usx2y: Fix potential NULL pointer dereference""
  dyndbg: drop uninformative vpr_info
  dyndbg: avoid calling dyndbg_emit_prefix when it has no work
  binder: Return EFAULT if we fail BINDER_ENABLE_ONEWAY_SPAM_DETECTION
  cdrom: gdrom: initialize global variable at init time
  brcmfmac: properly check for bus register errors
  Revert "brcmfmac: add a check for the status of usb_register"
  video: imsttfb: check for ioremap() failures
  Revert "video: imsttfb: fix potential NULL pointer dereferences"
  net: liquidio: Add missing null pointer checks
  Revert "net: liquidio: fix a NULL pointer dereference"
  media: gspca: properly check for errors in po1030_probe()
  Revert "media: gspca: Check the return value of write_bridge for timeout"
  media: gspca: mt9m111: Check write_bridge for timeout
  Revert "media: gspca: mt9m111: Check write_bridge for timeout"
  media: dvb: Add check on sp8870_readreg return
  ...

tty: vt: always invoke vc->vc_sw->con_resize callback

2021-05-15T15:12:12+00:00

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 
  #include 
  #include 
  #include 
  #include 
  #include 

  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 
Suggested-by: Linus Torvalds 
Signed-off-by: Tetsuo Handa 
Tested-by: syzbot 
Signed-off-by: Linus Torvalds

video: imsttfb: check for ioremap() failures

2021-05-13T16:58:39+00:00

We should check if ioremap() were to somehow fail in imsttfb_probe() and
handle the unwinding of the resources allocated here properly.

Ideally if anyone cares about this driver (it's for a PowerMac era PCI
display card), they wouldn't even be using fbdev anymore.  Or the devm_*
apis could be used, but that's just extra work for diminishing
returns...

Cc: Finn Thain 
Cc: Bartlomiej Zolnierkiewicz 
Reviewed-by: Rob Herring 
Link: https://lore.kernel.org/r/20210503115736.2104747-68-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

Revert "video: imsttfb: fix potential NULL pointer dereferences"

2021-05-13T16:58:38+00:00

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 
Cc: Aditya Pakki 
Cc: Finn Thain 
Cc: Bartlomiej Zolnierkiewicz 
Reviewed-by: Rob Herring 
Fixes: 1d84353d205a ("video: imsttfb: fix potential NULL pointer dereferences")
Cc: stable 
Link: https://lore.kernel.org/r/20210503115736.2104747-67-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

video: hgafb: fix potential NULL pointer dereference

2021-05-13T15:33:55+00:00

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 
Cc: Bartlomiej Zolnierkiewicz 
Cc: stable 
Signed-off-by: Igor Matheus Andrade Torrente 
Link: https://lore.kernel.org/r/20210503115736.2104747-40-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

Revert "video: hgafb: fix potential NULL pointer dereference"

2021-05-13T15:33:53+00:00

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 
Cc: Aditya Pakki 
Cc: Ferenc Bakonyi 
Cc: Bartlomiej Zolnierkiewicz 
Fixes: ec7f6aad57ad ("video: hgafb: fix potential NULL pointer dereference")
Cc: stable 
Link: https://lore.kernel.org/r/20210503115736.2104747-39-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman