Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
  ESR = 0x0000000086000006
  EC = 0x21: IABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
user pgtable: 4k pages, 48-bit VAs, pgdp=0000000052594000
[0000000000000000] pgd=0800000045d76003, p4d=0800000045d76003, pud=0800000047bb2003, pmd=0000000000000000
Internal error: Oops: 86000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 31956 Comm: syz-executor.0 Not tainted 5.19.0-syzkaller-13215-geb555cb5b794 #0
Hardware name: linux,dummy-virt (DT)
pstate: 60400809 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=-c)
pc : 0x0
lr : gsmld_receive_buf+0xb8/0x164 drivers/tty/n_gsm.c:2861
sp : ffff80000ed03cb0
x29: ffff80000ed03cb0 x28: f1ff000007aff000 x27: ffff80000ed03d70
x26: f2ff0000124f9000 x25: 0000000000000001 x24: ffff800009f7d690
x23: f5ff000012e36800 x22: ffff80000a52b37f x21: 0000000000000000
x20: ffff80000ed03d71 x19: ffff80000ed03d70 x18: 00000000fffffffb
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000020
x14: 0000000000000000 x13: ffff80000ed03d78 x12: ffff80000ed03d3a
x11: 0000000000000000 x10: 0000000000000066 x9 : 000000000000005c
x8 : ffff8000080102a4 x7 : ffff80000ed038e4 x6 : 0000000000000003
x5 : 000000000000541b x4 : ffff80000a67c000 x3 : 00000000000000ff
x2 : 0000000000000000 x1 : 0000000000000000 x0 : f2ff0000124f9000
Call trace:
 0x0
 tiocsti drivers/tty/tty_io.c:2293 [inline]
 tty_ioctl+0x834/0xd80 drivers/tty/tty_io.c:2692
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0xa8/0xf0 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52
 el0_svc_common.constprop.0+0x44/0xec arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x2c/0xc0 arch/arm64/kernel/syscall.c:206
 el0_svc+0x2c/0xb4 arch/arm64/kernel/entry-common.c:624
 el0t_64_sync_handler+0x1ac/0x1b0 arch/arm64/kernel/entry-common.c:642
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:581
Code: bad PC value
---[ end trace 0000000000000000 ]---