[v5.15] Internal error in __receive_fd

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c79648372d02 Linux 5.15.189
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=130c9434580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=b2d75bbb97809f3a6857
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7ab49562317a/disk-c7964837.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e847ec1e38d3/vmlinux-c7964837.xz
kernel image: https://storage.googleapis.com/syzbot-assets/263158c6371c/Image-c7964837.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b2d75b...@syzkaller.appspotmail.com

Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4166 Comm: syz.3.4 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 42400405 (nZcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=jc)
pc : __receive_fd+0x18c/0x28c fs/file.c:1196
lr : __receive_fd+0x168/0x28c fs/file.c:1195
sp : ffff800020187500
x29: ffff800020187500 x28: dfff800000000000 x27: 0000000000000000
x26: 0000000000000000 x25: 00000020002f9000 x24: dfff800000000000
x23: 00000000fffffff2 x22: 0000000020002f90 x21: ffff0000d770b680
x20: 0000000000000005 x19: ffff0000d919d400 x18: 0000000000000000
x17: ffff800016d04000 x16: ffff800008952294 x15: ffff8000167e4500
x14: ffff0000d770c080 x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000020002f90 x9 : 0000ffffffffffff
x8 : 0000000020002f90 x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
__receive_fd+0x18c/0x28c fs/file.c:1195
receive_fd_user include/linux/file.h:105 [inline]
scm_detach_fds+0x188/0x7f8 net/core/scm.c:324
scm_recv+0x348/0x460 include/net/scm.h:151
__unix_dgram_recvmsg+0x7d8/0xb28 net/unix/af_unix.c:2392
unix_dgram_recvmsg+0xd4/0xec net/unix/af_unix.c:2413
____sys_recvmsg+0x254/0x794 net/socket.c:-1
___sys_recvmsg+0x1ac/0x220 net/socket.c:2697
__sys_recvmsg net/socket.c:2727 [inline]
__do_sys_recvmsg net/socket.c:2737 [inline]
__se_sys_recvmsg net/socket.c:2734 [inline]
__arm64_sys_recvmsg+0x1a4/0x250 net/socket.c:2734
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: d503229f 2a1f03f7 2a1f03e0 b8000954 (2a1703e1)
---[ end trace d7f432ef5f88603f ]---
----------------
Code disassembly (best guess):
0: d503229f csdb
4: 2a1f03f7 mov w23, wzr
8: 2a1f03e0 mov w0, wzr
c: b8000954 sttr w20, [x10]
* 10: 2a1703e1 mov w1, w23 <-- trapping instruction


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: c79648372d02 Linux 5.15.189
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=179ab434580000

kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=b2d75bbb97809f3a6857
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13c5f2f0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=177829a2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7ab49562317a/disk-c7964837.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e847ec1e38d3/vmlinux-c7964837.xz
kernel image: https://storage.googleapis.com/syzbot-assets/263158c6371c/Image-c7964837.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b2d75b...@syzkaller.appspotmail.com

Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:

CPU: 0 PID: 4182 Comm: syz.0.17 Not tainted 5.15.189-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 42400405 (nZcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=jc)
pc : __receive_fd+0x18c/0x28c fs/file.c:1196
lr : __receive_fd+0x168/0x28c fs/file.c:1195

sp : ffff80001fd57500
x29: ffff80001fd57500 x28: dfff800000000000 x27: 0000000000000000

x26: 0000000000000000 x25: 00000020002f9000 x24: dfff800000000000

x23: 00000000fffffff2 x22: 0000000020002f90 x21: ffff0000d69bb680
x20: 0000000000000005 x19: ffff0000ceaec000 x18: 0000000000000000

x17: ffff800016d04000 x16: ffff800008952294 x15: ffff8000167e4500

x14: ffff0000d69bc080 x13: 1ffff0000282e06b x12: 0000000000ff0100

---[ end trace f34a1244306b5af9 ]---

----------------
Code disassembly (best guess):
0: d503229f csdb
4: 2a1f03f7 mov w23, wzr
8: 2a1f03e0 mov w0, wzr
c: b8000954 sttr w20, [x10]
* 10: 2a1703e1 mov w1, w23 <-- trapping instruction


---

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