================================================================== BUG: KMSAN: uninit-value in capi_write+0x791/0xa90 drivers/isdn/capi/capi.c:700 CPU: 0 PID: 12405 Comm: syz-executor.1 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x191/0x1f0 lib/dump_stack.c:113 kmsan_report+0x162/0x2d0 mm/kmsan/kmsan_report.c:109 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:294 capi_write+0x791/0xa90 drivers/isdn/capi/capi.c:700 __vfs_write+0x1a9/0xcb0 fs/read_write.c:494 vfs_write+0x481/0x920 fs/read_write.c:558 ksys_write+0x265/0x430 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:620 __x64_sys_write+0x4a/0x70 fs/read_write.c:620 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x4598e9 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2f96cf8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2f96cf96d4 R13: 00000000004c9c52 R14: 00000000004e1400 R15: 00000000ffffffff Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:189 [inline] kmsan_internal_poison_shadow+0x58/0xb0 mm/kmsan/kmsan.c:148 kmsan_slab_alloc+0xaa/0x120 mm/kmsan/kmsan_hooks.c:175 slab_alloc_node mm/slub.c:2790 [inline] __kmalloc_node_track_caller+0xb55/0x1320 mm/slub.c:4388 __kmalloc_reserve net/core/skbuff.c:141 [inline] __alloc_skb+0x306/0xa10 net/core/skbuff.c:209 alloc_skb include/linux/skbuff.h:1056 [inline] capi_write+0x12f/0xa90 drivers/isdn/capi/capi.c:691 __vfs_write+0x1a9/0xcb0 fs/read_write.c:494 vfs_write+0x481/0x920 fs/read_write.c:558 ksys_write+0x265/0x430 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:620 __x64_sys_write+0x4a/0x70 fs/read_write.c:620 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x63/0xe7 ==================================================================