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Unable to handle kernel write to read-only memory at virtual address ADDR (3)

Status: closed as invalid on 2026/03/06 16:20
Subsystems: net
[Documentation on labels]
First crash: 37d, last: 37d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 Unable to handle kernel write to read-only memory at virtual address ADDR -1 syz error 2 60d 99d 0/3 upstream: reported syz repro on 2025/12/02 02:17
upstream Unable to handle kernel write to read-only memory at virtual address ADDR udf -1 C 11 1124d 1261d 0/29 auto-obsoleted due to no activity on 2023/06/11 03:59
upstream Unable to handle kernel write to read-only memory at virtual address ADDR (2) net lsm -1 1 246d 245d 29/29 fixed on 2025/09/04 16:57

Sample crash report:
Unable to handle kernel write to read-only memory at virtual address ffff7fffe2c40000
KASAN: probably wild-memory-access in range [0xffffffff16200000-0xffffffff16200007]
Mem abort info:
  ESR = 0x000000009600004f
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x0f: level 3 permission fault
Data abort info:
  ISV = 0, ISS = 0x0000004f, ISS2 = 0x00000000
  CM = 0, WnR = 1, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000047334000
[ffff7fffe2c40000] pgd=0000000000000000, p4d=10000000ba0d5403, pud=10000000492a3403, pmd=00000000492a2003, pte=00600000492a6783
Internal error: Oops: 000000009600004f [#1]  SMP
Modules linked in:
CPU: 1 UID: 0 PID: 9427 Comm: syz.7.1920 Not tainted syzkaller #0 PREEMPT 
Hardware name: linux,dummy-virt (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __ll_sc__cmpxchg_case_mb_64 arch/arm64/include/asm/atomic_ll_sc.h:293 [inline]
pc : __cmpxchg_case_mb_64 arch/arm64/include/asm/cmpxchg.h:129 [inline]
pc : __cmpxchg_mb arch/arm64/include/asm/cmpxchg.h:171 [inline]
pc : rt_cache_route+0x130/0x190 net/ipv4/route.c:1506
lr : instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
lr : rt_cache_route+0x94/0x190 net/ipv4/route.c:1506
sp : ffff8000a11b75c0
x29: ffff8000a11b75c0 x28: ffff000057cb7664 x27: ffff0000160a0d08
x26: 0000000000000001 x25: 00000000656c6966 x24: 0000000000000000
x23: 0000000000000000 x22: ffff000057cb7640 x21: 0000000000000000
x20: ffff000057cb7600 x19: ffff7fffe2c40000 x18: ffff0000160a0d19
x17: ffff800084ddbf10 x16: ffff8000852edaec x15: ffff800084c760e8
x14: ffff800084c7523c x13: ffff800089bc9370 x12: ffff6ffffc588001
x11: 1fffeffffc588000 x10: ffff6ffffc588000 x9 : dfff800000000000
x8 : ffff7fffe2c40007 x7 : 0000000000000001 x6 : ffff6ffffc588000
x5 : ffff7fffe2c40000 x4 : ffff6ffffc588001 x3 : ffff800084c6cc84
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 __ll_sc__cmpxchg_case_mb_64 arch/arm64/include/asm/atomic_ll_sc.h:293 [inline] (P)
 __cmpxchg_case_mb_64 arch/arm64/include/asm/cmpxchg.h:129 [inline] (P)
 __cmpxchg_mb arch/arm64/include/asm/cmpxchg.h:171 [inline] (P)
 rt_cache_route+0x130/0x190 net/ipv4/route.c:1506 (P)
 rt_set_nexthop.isra.0+0x35c/0xdc0 net/ipv4/route.c:1621
 __mkroute_output net/ipv4/route.c:2681 [inline]
 ip_route_output_key_hash_rcu+0xab0/0x1de8 net/ipv4/route.c:2875
 ip_route_output_key_hash+0x10c/0x210 net/ipv4/route.c:2705
 __ip_route_output_key include/net/route.h:169 [inline]
 ip_route_output_flow+0x28/0x160 net/ipv4/route.c:2932
 l2tp_ip_sendmsg+0xac4/0x1424 net/l2tp/l2tp_ip.c:502
 inet_sendmsg+0x90/0xe0 net/ipv4/af_inet.c:859
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0xc8/0x168 net/socket.c:742
 ____sys_sendmsg+0x524/0x730 net/socket.c:2592
 ___sys_sendmsg+0x124/0x1a4 net/socket.c:2646
 __sys_sendmsg+0x118/0x1a4 net/socket.c:2678
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __arm64_sys_sendmsg+0x70/0xa0 net/socket.c:2681
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x70/0x260 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x29c arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
Code: f9800271 c85f7e60 ca150001 b5000081 (c801fe74) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	f9800271 	prfm	pstl1strm, [x19]
   4:	c85f7e60 	ldxr	x0, [x19]
   8:	ca150001 	eor	x1, x0, x21
   c:	b5000081 	cbnz	x1, 0x1c
* 10:	c801fe74 	stlxr	w1, x20, [x19] <-- trapping instruction

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/01 19:24 upstream 162b42445b58 6b8752f2 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64 Unable to handle kernel write to read-only memory at virtual address ADDR
* Struck through repros no longer work on HEAD.