d78bd6cc68
syzbot repored this bug in the softcursor code: BUG: KASAN: null-ptr-deref in soft_cursor+0x384/0x6b4 drivers/video/fbdev/core/softcursor.c:70 Read of size 16 at addr 0000000000000200 by task kworker/u4:1/12 CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.4.0-rc3-syzkaller-geb0f1697d729 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 Workqueue: events_power_efficient fb_flashcursor Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_report+0xe4/0x514 mm/kasan/report.c:465 kasan_report+0xd4/0x130 mm/kasan/report.c:572 kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:187 __asan_memcpy+0x3c/0x84 mm/kasan/shadow.c:105 soft_cursor+0x384/0x6b4 drivers/video/fbdev/core/softcursor.c:70 bit_cursor+0x113c/0x1a64 drivers/video/fbdev/core/bitblit.c:377 fb_flashcursor+0x35c/0x54c drivers/video/fbdev/core/fbcon.c:380 process_one_work+0x788/0x12d4 kernel/workqueue.c:2405 worker_thread+0x8e0/0xfe8 kernel/workqueue.c:2552 kthread+0x288/0x310 kernel/kthread.c:379 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:853 This fix let bit_cursor() bail out early when a font bitmap isn't available yet. Signed-off-by: Helge Deller <deller@gmx.de> Reported-by: syzbot+d910bd780e6efac35869@syzkaller.appspotmail.com Acked-by: Sam Ravnborg <sam@ravnborg.org> Cc: stable@kernel.org |
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| .. | ||
| Makefile | ||
| bitblit.c | ||
| cfbcopyarea.c | ||
| cfbfillrect.c | ||
| cfbimgblt.c | ||
| fb_cmdline.c | ||
| fb_ddc.c | ||
| fb_defio.c | ||
| fb_draw.h | ||
| fb_notify.c | ||
| fb_sys_fops.c | ||
| fbcmap.c | ||
| fbcon.c | ||
| fbcon.h | ||
| fbcon_ccw.c | ||
| fbcon_cw.c | ||
| fbcon_rotate.c | ||
| fbcon_rotate.h | ||
| fbcon_ud.c | ||
| fbcvt.c | ||
| fbmem.c | ||
| fbmon.c | ||
| fbsysfs.c | ||
| modedb.c | ||
| softcursor.c | ||
| svgalib.c | ||
| syscopyarea.c | ||
| sysfillrect.c | ||
| sysimgblt.c | ||
| tileblit.c | ||