Some additional information: Excerpt from my smb.conf:
unix extensions = no wide links = yes kernel oplocks = yes use sendfile = yes ea support = no Notably, `kernel oplocks = yes` is not the default, which may explain why only some people appear to be affected by this issue. Running Debian kernel 6.12.17-amd64. My smbd log follows. Note in particular the first 2 lines about a linux kernel oplock error - these lines are missing from the original report: Mar 17 18:50:10 smbd[12006]: [2025/03/17 18:50:10.955307, 0] source3/smbd/oplock_linux.c:168(linux_release_kernel_oplock) Mar 17 18:50:10 smbd[12006]: linux_release_kernel_oplock: Error when removing kernel oplock on file ., file_id = 41:4:0, gen_id = 1481. Error was Invalid argument Mar 17 18:50:10 smbd[12006]: [2025/03/17 18:50:10.955749, 0] source3/smbd/smb2_oplock.c:157(release_file_oplock) Mar 17 18:50:10 smbd[12006]: PANIC: assert failed at source3/smbd/smb2_oplock.c(157): sconn->oplocks.level_II_open>=0 Mar 17 18:50:10 smbd[12006]: [2025/03/17 18:50:10.955888, 0] lib/util/fault.c:178(smb_panic_log) Mar 17 18:50:10 smbd[12006]: =============================================================== Mar 17 18:50:10 smbd[12006]: [2025/03/17 18:50:10.955947, 0] lib/util/fault.c:179(smb_panic_log) Mar 17 18:50:10 smbd[12006]: INTERNAL ERROR: assert failed: sconn->oplocks.level_II_open>=0 in smbd (smbd[10.172.1.2) (client [10.172.1.2]) pid 12006 (4.22.0-Debian-4.22.0+dfsg-1+b1) Mar 17 18:50:10 smbd[12006]: [2025/03/17 18:50:10.956007, 0] lib/util/fault.c:186(smb_panic_log) Mar 17 18:50:10 smbd[12006]: If you are running a recent Samba version, and if you think this problem is not yet fixed in the latest versions, please consider reporting this bug, see https://wiki.samba.org/index.php/Bug_Reporting Mar 17 18:50:10 smbd[12006]: [2025/03/17 18:50:10.956067, 0] lib/util/fault.c:191(smb_panic_log) Mar 17 18:50:10 smbd[12006]: =============================================================== Mar 17 18:50:10 smbd[12006]: [2025/03/17 18:50:10.956118, 0] lib/util/fault.c:192(smb_panic_log) Mar 17 18:50:10 smbd[12006]: PANIC (pid 12006): assert failed: sconn->oplocks.level_II_open>=0 in 4.22.0-Debian-4.22.0+dfsg-1+b1 Mar 17 18:50:10 smbd[12006]: [2025/03/17 18:50:10.958600, 0] lib/util/fault.c:303(log_stack_trace) Mar 17 18:50:10 smbd[12006]: BACKTRACE: 26 stack frames: Mar 17 18:50:10 smbd[12006]: #0 /usr/lib/x86_64-linux-gnu/samba/libgenrand-private-samba.so.0(log_stack_trace+0x2d) [0x7f968d2285bd] Mar 17 18:50:10 smbd[12006]: #1 /usr/lib/x86_64-linux-gnu/samba/libgenrand-private-samba.so.0(smb_panic+0xd) [0x7f968d22885d] Mar 17 18:50:10 smbd[12006]: #2 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base-private-samba.so.0(release_file_oplock+0x122) [0x7f968d6caf72] Mar 17 18:50:10 smbd[12006]: #3 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base-private-samba.so.0(close_file_smb+0x6f8) [0x7f968d66a018] Mar 17 18:50:10 smbd[12006]: #4 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base-private-samba.so.0(+0xc33a5) [0x7f968d6a33a5] Mar 17 18:50:10 smbd[12006]: #5 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base-private-samba.so.0(smbd_smb2_request_process_close+0x1ee) [0x7f968d6a3d8e] Mar 17 18:50:10 smbd[12006]: #6 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base-private-samba.so.0(smbd_smb2_request_dispatch+0x1b04) [0x7f968d696184] Mar 17 18:50:10 smbd[12006]: #7 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base-private-samba.so.0(+0xb77f2) [0x7f968d6977f2] Mar 17 18:50:10 smbd[12006]: #8 /lib/x86_64-linux-gnu/libtevent.so.0(tevent_common_invoke_fd_handler+0x95) [0x7f968d396815] Mar 17 18:50:10 smbd[12006]: #9 /lib/x86_64-linux-gnu/libtevent.so.0(+0xfa56) [0x7f968d39da56] Mar 17 18:50:10 smbd[12006]: #10 /lib/x86_64-linux-gnu/libtevent.so.0(+0xd48b) [0x7f968d39b48b] Mar 17 18:50:10 smbd[12006]: #11 /lib/x86_64-linux-gnu/libtevent.so.0(_tevent_loop_once+0x93) [0x7f968d395953] Mar 17 18:50:10 smbd[12006]: #12 /lib/x86_64-linux-gnu/libtevent.so.0(tevent_common_loop_wait+0x1b) [0x7f968d395c4b] Mar 17 18:50:10 smbd[12006]: #13 /lib/x86_64-linux-gnu/libtevent.so.0(+0xd41b) [0x7f968d39b41b] Mar 17 18:50:10 smbd[12006]: #14 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base-private-samba.so.0(smbd_process+0x895) [0x7f968d6840e5] Mar 17 18:50:10 smbd[12006]: #15 smbd: client [10.172.1.2](+0xa1e7) [0x55adcbde31e7] Mar 17 18:50:10 smbd[12006]: #16 /lib/x86_64-linux-gnu/libtevent.so.0(tevent_common_invoke_fd_handler+0x95) [0x7f968d396815] Mar 17 18:50:10 smbd[12006]: #17 /lib/x86_64-linux-gnu/libtevent.so.0(+0xfa56) [0x7f968d39da56] Mar 17 18:50:10 smbd[12006]: #18 /lib/x86_64-linux-gnu/libtevent.so.0(+0xd48b) [0x7f968d39b48b] Mar 17 18:50:10 smbd[12006]: #19 /lib/x86_64-linux-gnu/libtevent.so.0(_tevent_loop_once+0x93) [0x7f968d395953] Mar 17 18:50:10 smbd[12006]: #20 /lib/x86_64-linux-gnu/libtevent.so.0(tevent_common_loop_wait+0x1b) [0x7f968d395c4b] Mar 17 18:50:10 smbd[12006]: #21 /lib/x86_64-linux-gnu/libtevent.so.0(+0xd41b) [0x7f968d39b41b] Mar 17 18:50:10 smbd[12006]: #22 smbd: client [10.172.1.2](main+0x14a0) [0x55adcbde0330] Mar 17 18:50:10 smbd[12006]: #23 /lib/x86_64-linux-gnu/libc.so.6(+0x29ca8) [0x7f968d006ca8] Mar 17 18:50:10 smbd[12006]: #24 /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x85) [0x7f968d006d65] Mar 17 18:50:10 smbd[12006]: #25 smbd: client [10.172.1.2](_start+0x21) [0x55adcbde0e31] Mar 17 18:50:10 smbd[12006]: [2025/03/17 18:50:10.959320, 0] source3/lib/dumpcore.c:318(dump_core) Mar 17 18:50:10 smbd[12006]: coredump is handled by helper binary specified at /proc/sys/kernel/core_pattern Mar 17 18:50:10 smbd[12006]: Mar 17 18:50:11 systemd-coredump[12135]: Process 12006 (smbd[10.172.1.2) of user 0 dumped core. Module libnss_systemd.so.2 from deb systemd-257.4-3.amd64 Module libzstd.so.1 from deb libzstd-1.5.7+dfsg-1.amd64 Module libgcc_s.so.1 from deb gcc-14-14.2.0-19.amd64 Module libstdc++.so.6 from deb gcc-14-14.2.0-19.amd64 Module libsystemd.so.0 from deb systemd-257.4-3.amd64 Stack trace of thread 12006: #0 0x00007f968d07195c __pthread_kill_implementation (libc.so.6 + 0x9495c) #1 0x00007f968d01ccc2 __GI_raise (libc.so.6 + 0x3fcc2) #2 0x00007f968d0054ac __GI_abort (libc.so.6 + 0x284ac) #3 0x00007f968d560894 dump_core (libsmbconf.so.0 + 0x5a894) #4 0x00007f968d556224 smb_panic_s3 (libsmbconf.so.0 + 0x50224) #5 0x00007f968d22886e smb_panic (libgenrand-private-samba.so.0 + 0x286e) #6 0x00007f968d6caf72 release_file_oplock (libsmbd-base-private-samba.so.0 + 0xeaf72) #7 0x00007f968d66a018 close_file_smb (libsmbd-base-private-samba.so.0 + 0x8a018) #8 0x00007f968d6a33a5 n/a (libsmbd-base-private-samba.so.0 + 0xc33a5) #9 0x00007f968d6a3d8e smbd_smb2_request_process_close (libsmbd-base-private-samba.so.0 + 0xc3d8e) #10 0x00007f968d696184 smbd_smb2_request_dispatch (libsmbd-base-private-samba.so.0 + 0xb6184) #11 0x00007f968d6977f2 n/a (libsmbd-base-private-samba.so.0 + 0xb77f2) #12 0x00007f968d396815 tevent_common_invoke_fd_handler (libtevent.so.0 + 0x8815) #13 0x00007f968d39da56 n/a (libtevent.so.0 + 0xfa56) #14 0x00007f968d39b48b n/a (libtevent.so.0 + 0xd48b) #15 0x00007f968d395953 _tevent_loop_once (libtevent.so.0 + 0x7953) #16 0x00007f968d395c4b tevent_common_loop_wait (libtevent.so.0 + 0x7c4b) #17 0x00007f968d39b41b n/a (libtevent.so.0 + 0xd41b) #18 0x00007f968d6840e5 smbd_process (libsmbd-base-private-samba.so.0 + 0xa40e5) #19 0x000055adcbde31e7 n/a (n/a + 0x0) ELF object binary architecture: AMD x86-64
