================================================================== BUG: KASAN: vmalloc-out-of-bounds in fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0xc28/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 Write of size 8 at addr ffff8000934d98a0 by task syz.1.688/8657 CPU: 0 UID: 0 PID: 8657 Comm: syz.1.688 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_st dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xb0/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0x8c/0xc4 mm/kasan/report.c:595 __asan_report_store8_noabort+0x20/0x2c mm/kasan/report_generic.c:386 fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] sys_imageblit+0xc28/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 drm_fbdev_shmem_defio_imageblit+0x38/0x144 drivers/gpu/drm/drm_fbdev_shmem.c:39 soft_cursor+0x534/0x6bc drivers/video/fbdev/core/softcursor.c:74 bit_cursor+0xaac/0x112c drivers/video/fbdev/core/bitblit.c:370 fbcon_cursor+0x344/0x498 drivers/video/fbdev/core/fbcon.c:1427 set_cursor+0x1a0/0x200 drivers/tty/vt/vt.c:896 con_flush_chars+0x84/0xc0 drivers/tty/vt/vt.c:3731 con_write+0x40/0x58 drivers/tty/vt/vt.c:3662 process_output_block drivers/tty/n_tty.c:557 [inline] n_tty_write+0x994/0xd90 drivers/tty/n_tty.c:2366 iterate_tty_write drivers/tty/tty_io.c:1006 [inline] file_tty_write+0x3dc/0x66c drivers/tty/tty_io.c:1054 tty_write+0x44/0x54 drivers/tty/tty_io.c:1075 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x51c/0xa0c fs/read_write.c:687 ksys_write+0x12c/0x228 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __arm64_sys_write+0x84/0x98 fs/read_write.c:747 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:758 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590 The buggy address belongs to a vmalloc virtual mapping Memory state around the buggy address: ffff8000934d9780: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffff8000934d9800: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >ffff8000934d9880: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffff8000934d9900: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffff8000934d9980: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== Unable to handle kernel paging request at virtual address ffff8000934d98a0 KASAN: probably user-memory-access in range [0x000000049a6cc500-0x000000049a6cc507] Mem abort info: ESR = 0x0000000096000047 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x07: level 3 translation fault Data abort info: ISV = 0, ISS = 0x00000047, ISS2 = 0x00000000 CM = 0, WnR = 1, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0 swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000021af03000 [ffff8000934d98a0] pgd=0000000000000000, p4d=1000000221211003, pud=1000000221212003, pmd=1000000106ade403, pte=0000000000000000 Internal error: Oops: 0000000096000047 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 8657 Comm: syz.1.688 Tainted: G B syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026 pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] pc : fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] pc : fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] pc : fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] pc : sys_imageblit+0xc30/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 lr : fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] lr : fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] lr : fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] lr : fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] lr : sys_imageblit+0xc28/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 sp : ffff800092bf7430 x29: ffff800092bf74b0 x28: dfff800000000000 x27: 0000000000000000 x26: ffff8000934d98a0 x25: ffff0000c67a54c0 x24: 0000000000000004 x23: 0000000000000000 x22: ffff8000934d98a0 x21: 0000000000000000 x20: ffff0000c67a54c1 x19: ffff800092bf7488 x18: 1fffe00035b9ec28 x17: 0000000000000003 x16: ffff800088bf7000 x15: ffff800088ca7ee0 x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000000 x11: 0000000000000000 x10: ffff700011481921 x9 : 0000000000000000 x8 : ffff0000d8f51d80 x7 : 0000000000000000 x6 : ffff80008048e314 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff8000802f8c58 x2 : 0000000000000000 x1 : ffff0000d8f51d80 x0 : ffff8000934d98a0 Call trace: fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:365 [inline] (P) fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] (P) fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] (P) sys_imageblit+0xc30/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 (P) drm_fbdev_shmem_defio_imageblit+0x38/0x144 drivers/gpu/drm/drm_fbdev_shmem.c:39 soft_cursor+0x534/0x6bc drivers/video/fbdev/core/softcursor.c:74 bit_cursor+0xaac/0x112c drivers/video/fbdev/core/bitblit.c:370 fbcon_cursor+0x344/0x498 drivers/video/fbdev/core/fbcon.c:1427 set_cursor+0x1a0/0x200 drivers/tty/vt/vt.c:896 con_flush_chars+0x84/0xc0 drivers/tty/vt/vt.c:3731 con_write+0x40/0x58 drivers/tty/vt/vt.c:3662 process_output_block drivers/tty/n_tty.c:557 [inline] n_tty_write+0x994/0xd90 drivers/tty/n_tty.c:2366 iterate_tty_write drivers/tty/tty_io.c:1006 [inline] file_tty_write+0x3dc/0x66c drivers/tty/tty_io.c:1054 tty_write+0x44/0x54 drivers/tty/tty_io.c:1075 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x51c/0xa0c fs/read_write.c:687 ksys_write+0x12c/0x228 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __arm64_sys_write+0x84/0x98 fs/read_write.c:747 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:758 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590 Code: aa1a03e0 97b6b80e aa1a03e0 d34416e9 (f8008415) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: aa1a03e0 mov x0, x26 4: 97b6b80e bl 0xfffffffffedae03c 8: aa1a03e0 mov x0, x26 c: d34416e9 ubfx x9, x23, #4, #2 * 10: f8008415 str x21, [x0], #8 <-- trapping instruction