kernel.git/drivers/video/fbdev/core/fbmem.c, branch linux-5.12.y

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

2021-07-20T14:02:01Z

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

drm: remove pgprot_decrypted() before calls to io_remap_pfn_range()

2020-11-10T16:19:14Z

commit f8f6ae5d077a ("mm: always have io_remap_pfn_range() set pgprot_decrypted()") moves the pgprot_decrypted() into io_remap_pfn_range(). Delete any, now confusing, open coded calls that directly precede io_remap_pfn_range(): - drm_io_prot() is only in drm_mmap_locked() to call io_remap_pfn_range() - fb_mmap() immediately calls vm_iomap_memory() which is a convenience wrapper for io_remap_pfn_range() Signed-off-by: Jason Gunthorpe Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/0-v1-2e6a0db57868+166-drm_sme_clean_jgg@nvidia.com

fbdev: simplify fb_getput_cmap()

2020-09-25T14:34:50Z

This function is one of the remaining users of compat_alloc_user_space() and copy_in_user(). Clean it up by copying to a local data structure copy instead, which also leads to more readable code. Signed-off-by: Arnd Bergmann Acked-by: Daniel Vetter Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200918100926.1447563-1-arnd@arndb.de

fbmem: add margin check to fb_check_caps()

2020-09-08T11:33:01Z

A fb_ioctl() FBIOPUT_VSCREENINFO call with invalid xres setting or yres setting in struct fb_var_screeninfo will result in a KASAN: vmalloc-out-of-bounds failure in bitfill_aligned() as the margins are being cleared. The margins are cleared in chunks and if the xres setting or yres setting is a value of zero upto the chunk size, the failure will occur. Add a margin check to validate xres and yres settings. Signed-off-by: George Kennedy Reported-by: syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com Reviewed-by: Dan Carpenter Cc: Dhaval Giani Signed-off-by: Bartlomiej Zolnierkiewicz Link: https://patchwork.freedesktop.org/patch/msgid/1594149963-13801-1-git-send-email-george.kennedy@oracle.com

Merge drm/drm-next into drm-misc-next

2020-08-12T18:42:08Z

Backmerging drm-next into drm-misc-next for nouveau and panel updates. Resolves a conflict between ttm and nouveau, where struct ttm_mem_res got renamed to struct ttm_resource. Signed-off-by: Thomas Zimmermann

fbmem: pull fbcon_update_vcs() out of fb_set_var()

2020-08-04T05:37:23Z

syzbot is reporting OOB read bug in vc_do_resize() [1] caused by memcpy() based on outdated old_{rows,row_size} values, for resize_screen() can recurse into vc_do_resize() which changes vc->vc_{cols,rows} that outdates old_{rows,row_size} values which were saved before calling resize_screen(). Daniel Vetter explained that resize_screen() should not recurse into fbcon_update_vcs() path due to FBINFO_MISC_USEREVENT being still set when calling resize_screen(). Instead of masking FBINFO_MISC_USEREVENT before calling fbcon_update_vcs(), we can remove FBINFO_MISC_USEREVENT by calling fbcon_update_vcs() only if fb_set_var() returned 0. This change assumes that it is harmless to call fbcon_update_vcs() when fb_set_var() returned 0 without reaching fb_notifier_call_chain(). [1] https://syzkaller.appspot.com/bug?id=c70c88cfd16dcf6e1d3c7f0ab8648b3144b5b25e Reported-and-tested-by: syzbot Suggested-by: Daniel Vetter Signed-off-by: Tetsuo Handa Reported-by: kernel test robot for missing #include Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/075b7e37-3278-cd7d-31ab-c5073cfa8e92@i-love.sakura.ne.jp

fbdev: Use fallthrough pseudo-keyword

2020-08-03T19:38:37Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200707210539.GA12530@embeddedor

fbdev: Remove trailing whitespace

2020-08-03T08:02:15Z

Removes trailing whitespaces in several places. Signed-off-by: Thomas Zimmermann Acked-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20200729134148.6855-2-tzimmermann@suse.de

fbmem: Adjust indentation in fb_prepare_logo and fb_blank

2020-01-15T16:31:47Z

Clang warns: ../drivers/video/fbdev/core/fbmem.c:665:3: warning: misleading indentation; statement is not part of the previous 'else' [-Wmisleading-indentation] if (fb_logo.depth > 4 && depth > 4) { ^ ../drivers/video/fbdev/core/fbmem.c:661:2: note: previous statement is here else ^ ../drivers/video/fbdev/core/fbmem.c:1075:3: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] return ret; ^ ../drivers/video/fbdev/core/fbmem.c:1072:2: note: previous statement is here if (!ret) ^ 2 warnings generated. This warning occurs because there are spaces before the tabs on these lines. Normalize the indentation in these functions so that it is consistent with the Linux kernel coding style and clang no longer warns. Fixes: 1692b37c99d5 ("fbdev: Fix logo if logo depth is less than framebuffer depth") Link: https://github.com/ClangBuiltLinux/linux/issues/825 Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Signed-off-by: Bartlomiej Zolnierkiewicz Link: https://patchwork.freedesktop.org/patch/msgid/20191218030025.10064-1-natechancellor@gmail.com

fbdev: potential information leak in do_fb_ioctl()

2020-01-15T16:31:39Z

The "fix" struct has a 2 byte hole after ->ywrapstep and the "fix = info->fix;" assignment doesn't necessarily clear it. It depends on the compiler. The solution is just to replace the assignment with an memcpy(). Fixes: 1f5e31d7e55a ("fbmem: don't call copy_from/to_user() with mutex held") Signed-off-by: Dan Carpenter Cc: Andrew Morton Cc: Arnd Bergmann Cc: "Eric W. Biederman" Cc: Andrea Righi Cc: Daniel Vetter Cc: Sam Ravnborg Cc: Maarten Lankhorst Cc: Daniel Thompson Cc: Peter Rosin Cc: Jani Nikula Cc: Gerd Hoffmann Signed-off-by: Bartlomiej Zolnierkiewicz Link: https://patchwork.freedesktop.org/patch/msgid/20200113100132.ixpaymordi24n3av@kili.mountain