6.1.119 on the same machine works fine. 6.1.121 on similar configurations works fine. 6.6.68 on the same machine works fine. Reproducable with: modprobe zram && rmmod zram Or: /etc/init.d/zram-init start (including at boot if configured) Or: zram-init 4096 [ 93.953643] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 93.954371] #PF: supervisor read access in kernel mode [ 93.955074] #PF: error_code(0x0000) - not-present page [ 93.955773] PGD 0 P4D 0 [ 93.956453] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 93.957133] CPU: 0 PID: 3187 Comm: rmmod Tainted: P O 6.1.122-gentoo-dist-hardened #1 (redacted) [ 93.966845] Call Trace: [ 93.967612] <TASK> [ 93.968379] ? __die_body.cold+0x1a/0x1f [ 93.969153] ? page_fault_oops+0x15c/0x2a0 [ 93.969928] ? __wake_up_common_lock+0x8d/0xd0 [ 93.970703] ? exc_page_fault+0x72/0x170 [ 93.971477] ? asm_exc_page_fault+0x22/0x30 [ 93.972253] ? zcomp_cpu_up_prepare+0xa0/0xa0 [zram] [ 93.973033] ? zcomp_cpu_dead+0x8/0x60 [zram] [ 93.973812] cpuhp_invoke_callback+0x91/0x430 [ 93.974592] cpuhp_issue_call+0xfc/0x170 [ 93.975369] __cpuhp_state_remove_instance+0xd5/0x190 [ 93.976149] zcomp_destroy+0x1c/0x30 [zram] [ 93.976934] zcomp_create+0xd4f/0x20d7 [zram] [ 93.977718] zcomp_create+0xde4/0x20d7 [zram] [ 93.978501] ? zcomp_create+0xf40/0x20d7 [zram] [ 93.979283] zcomp_create+0xf4d/0x20d7 [zram] [ 93.980068] idr_for_each+0x6b/0xf0 [ 93.980852] zcomp_create+0x2074/0x20d7 [zram] [ 93.981637] __x64_sys_delete_module+0x19e/0x2e0 [ 93.982421] do_syscall_64+0x56/0x80 [ 93.983206] ? clear_bhb_loop+0x15/0x70 [ 93.983987] ? clear_bhb_loop+0x15/0x70 [ 93.984764] ? clear_bhb_loop+0x15/0x70 [ 93.985538] ? clear_bhb_loop+0x15/0x70 [ 93.986310] ? clear_bhb_loop+0x15/0x70 [ 93.987076] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 (redacted) [ 94.013285] Kernel panic - not syncing: Fatal exception [ 94.014253] Kernel Offset: (redacted)
Verified that system with 6.1.121 reproduces this crash after updating to 6.1.122.
Upstream reports: https://lore.kernel.org/all/7rferqxnhaa4rgpgmwm3ulhssdvnxhzz7fyjo3u2fmw3jyqgjw@oimhw7h6idf2/T/