================================================================== 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 ffff800093a69000 by task syz.6.615/8219 CPU: 1 UID: 0 PID: 8219 Comm: syz.6.615 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP 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_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:1434 hide_cursor+0xdc/0x2d0 drivers/tty/vt/vt.c:883 do_con_write+0x1bc/0x4264 drivers/tty/vt/vt.c:3301 con_write+0x34/0x58 drivers/tty/vt/vt.c:3661 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+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606 The buggy address belongs to a 0-page vmalloc region starting at 0xffff800093769000 allocated at drm_gem_shmem_vmap_locked+0x45c/0x690 drivers/gpu/drm/drm_gem_shmem_helper.c:415 Memory state around the buggy address: ffff800093a68f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff800093a68f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff800093a69000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffff800093a69080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffff800093a69100: 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 ffff800093a69000 KASAN: probably user-memory-access in range [0x000000049d348000-0x000000049d348007] 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=000000021b181000 [ffff800093a69000] pgd=0000000000000000, p4d=1000000221494003, pud=1000000221495003, pmd=1000000106b47403, pte=0000000000000000 Internal error: Oops: 0000000096000047 [#1] SMP Modules linked in: CPU: 1 UID: 0 PID: 8219 Comm: syz.6.615 Tainted: G B L syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP 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 : ffff8000945d7050 x29: ffff8000945d70d0 x28: dfff800000000000 x27: 0000000000000000 x26: ffff800093a69000 x25: ffff0000c6c15c80 x24: 0000000000000004 x23: 0000000000000000 x22: ffff800093a69000 x21: 0000000000000000 x20: ffff0000c6c15c81 x19: ffff8000945d70a8 x18: 1fffe00035bd9828 x17: 3d3d3d3d3d3d3d3d x16: 3d3d3d3d3d3d3d3d x15: 3d3d3d3d3d3d3d3d x14: 00000000000013e8 x13: 0000000000000001 x12: 0000000000000000 x11: 0000000000000000 x10: ffff700011451b21 x9 : 0000000000000000 x8 : ffff0000d0c01d80 x7 : 0000000000000000 x6 : ffff800080483190 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff8000802f394c x2 : 0000000000000000 x1 : ffff0000d0c01d80 x0 : ffff800093a69000 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:1434 hide_cursor+0xdc/0x2d0 drivers/tty/vt/vt.c:883 do_con_write+0x1bc/0x4264 drivers/tty/vt/vt.c:3301 con_write+0x34/0x58 drivers/tty/vt/vt.c:3661 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+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606 Code: aa1a03e0 97b7aa67 aa1a03e0 d34416e9 (f8008415) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: aa1a03e0 mov x0, x26 4: 97b7aa67 bl 0xfffffffffedea9a0 8: aa1a03e0 mov x0, x26 c: d34416e9 ubfx x9, x23, #4, #2 * 10: f8008415 str x21, [x0], #8 <-- trapping instruction