On 29.04.22 13:50, Naresh Kamboju wrote:

Following kernel BUG noticed on Linux next-20220428 on x86_64 while running selftests x86 fsgsbase_64 test cases.

Reported-by: Linux Kernel Functional Testing lkft@linaro.org

My gut feeling is that this could be related to the maple tree patches, but might be just wrong.

Test log:

# selftests: x86: fsgsbase_64 # [OK] GSBASE started at 1 # [RUN] Set GS = 0x7, read GSBASE # [OK] GSBASE reads as 0x1 with invalid GS # FSGSBASE instructions are enabled # [RUN] ARCH_SET_GS to 0x0 # [OK] GSBASE was set as expected (selector 0x0) # [OK] ARCH_GET_GS worked as expected (selector 0x0) # [RUN] ARCH_SET_GS to 0x1 # [OK] GSBASE was set as expected (selector 0x0) # [OK] ARCH_GET_GS worked as exp[ 199.295202] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 199.302779] #PF: supervisor read access in kernel mode [ 199.307918] #PF: error_code(0x0000) - not-present page [ 199.313057] PGD 8000000145f05067 P4D 8000000145f05067 PUD 145f04067 PMD 0 [ 199.319930] Oops: 0000 [#1] PREEMPT SMP PTI [ 199.324117] CPU: 1 PID: 2948 Comm: sysret_rip_64 Tainted: G K 5.18.0-rc4-next-20220428 #1 [ 199.333587] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 199.340972] RIP: 0010:copy_vma+0x61/0x220 [ 199.344983] Code: 48 89 45 d0 31 c0 49 8b 07 49 83 7f 60 00 48 89 45 b8 0f 84 47 01 00 00 48 8d 55 c8 4c 89 ee 4c 89 f7 4c 01 eb e8 2f ec ff ff <48> 39 18 72 7e 4d 8b 47 20 4d 8b 4f 58 6a 00 48 89 d9 41 ff b7 90 [ 199.363722] RSP: 0018:ffffacf8813bfca0 EFLAGS: 00010292 [ 199.368946] RAX: 0000000000000000 RBX: 00007fffffffe000 RCX: 0000000000000001 [ 199.376070] RDX: ffffffffffffffff RSI: ffff9c6d04959f00 RDI: ffffacf8813bfc38 [ 199.383193] RBP: ffffacf8813bfcf0 R08: 000000000000000b R09: 000000000000000b [ 199.390317] R10: ffff9c6d03e392f0 R11: 0000000000000058 R12: ffffacf8813bfd48 [ 199.397441] R13: 00007fffffffd000 R14: ffff9c6ccc331d40 R15: ffff9c6d03e392f0 [ 199.404566] FS: 00007fce67a16b80(0000) GS:ffff9c6e2fa80000(0000) knlGS:0000000000000000 [ 199.412644] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 199.418391] CR2: 0000000000000000 CR3: 0000000156398002 CR4: 00000000003706e0 [ 199.425521] DR0: 00000000006021a8 DR1: 0000000000400ae9 DR2: 0000000000000000 [ 199.432647] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 [ 199.439778] Call Trace: [ 199.442221] <TASK> [ 199.444320] move_vma+0x131/0x4a0 [ 199.447644] __do_sys_mremap+0x35c/0x890 [ 199.451578] ? syscall_trace_enter.constprop.0+0x176/0x230 [ 199.457068] __x64_sys_mremap+0x25/0x30 [ 199.460907] do_syscall_64+0x5c/0x80 [ 199.464486] ? do_syscall_64+0x69/0x80 [ 199.468239] ? syscall_exit_to_user_mode+0x3a/0x50 [ 199.473031] ? do_syscall_64+0x69/0x80 [ 199.476786] ? asm_exc_general_protection+0x8/0x30 [ 199.481576] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 199.486631] RIP: 0033:0x7fce66f10bda [ 199.490208] Code: 73 01 c3 48 8b 0d be a2 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 19 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8e a2 2b 00 f7 d8 64 89 01 48 [ 199.508952] RSP: 002b:00007ffd71e44b28 EFLAGS: 00000206 ORIG_RAX: 0000000000000019 [ 199.516511] RAX: ffffffffffffffda RBX: 00007fffffffd000 RCX: 00007fce66f10bda [ 199.523634] RDX: 0000000000001000 RSI: 0000000000001000 RDI: 0000000000402000 [ 199.530757] RBP: 0000000000000001 R08: 00007fffffffd000 R09: 00007ffd71e449fc [ 199.537883] R10: 0000000000000003 R11: 0000000000000206 R12: 0000000000000001 [ 199.545016] R13: 00007ffd71e44ce0 R14: 0000000000000000 R15: 0000000000000000 [ 199.552150] </TASK> [ 199.554341] Modules linked in: x86_pkg_temp_thermal fuse [last unloaded: test_klp_livepatch] [ 199.562772] CR2: 0000000000000000 ected (selector [ 199.566084] ---[ end trace 0000000000000000 ]--- [ 199.566085] RIP: 0010:copy_vma+0x61/0x220 0x0) # [RUN] AR[ 199.566088] Code: 48 89 45 d0 31 c0 49 8b 07 49 83 7f 60 00 48 89 45 b8 0f 84 47 01 00 00 48 8d 55 c8 4c 89 ee 4c 89 f7 4c 01 eb e8 2f ec ff ff <48> 39 18 72 7e 4d 8b 47 20 4d 8b 4f 58 6a 00 48 89 d9 41 ff b7 90 [ 199.566089] RSP: 0018:ffffacf8813bfca0 EFLAGS: 00010292 CH_SET_GS to 0x2[ 199.566090] RAX: 0000000000000000 RBX: 00007fffffffe000 RCX: 0000000000000001 [ 199.566091] RDX: ffffffffffffffff RSI: ffff9c6d04959f00 RDI: ffffacf8813bfc38 00000000 # [OK][ 199.566092] RBP: ffffacf8813bfcf0 R08: 000000000000000b R09: 000000000000000b GSBASE was set [ 199.566092] R10: ffff9c6d03e392f0 R11: 0000000000000058 R12: ffffacf8813bfd48 [ 199.566093] R13: 00007fffffffd000 R14: ffff9c6ccc331d40 R15: ffff9c6d03e392f0 as expected (sel[ 199.566094] FS: 00007fce67a16b80(0000) GS:ffff9c6e2fa80000(0000) knlGS:0000000000000000 [ 199.566095] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 ector 0x0) # [O[ 199.566096] CR2: 0000000000000000 CR3: 0000000156398002 CR4: 00000000003706e0 [ 199.566097] DR0: 00000000006021a8 DR1: 0000000000400ae9 DR2: 0000000000000000 K] ARCH_GET_GS w[ 199.566098] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 orked as expected (selector 0x0) # [RUN] ARCH_SET_GS to 0x0 # [OK] GSBASE was set as expected (selector 0x0) # [OK] ARCH_GET_GS worked as expected (selector 0x0)

metadata: git_ref: master git_repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next git_sha: bdc61aad77faf67187525028f1f355eff3849f22 git_describe: next-20220428 kernel_version: 5.18.0-rc4 kernel-config: https://builds.tuxbuild.com/28Pz4BMeY7pEp28bl5hC46lwjpe/config vmlinux : https://builds.tuxbuild.com/28Pz4BMeY7pEp28bl5hC46lwjpe/vmlinux.xz System.map : https://builds.tuxbuild.com/28Pz4BMeY7pEp28bl5hC46lwjpe/System.map

Reported-by: Linux Kernel Functional Testing lkft@linaro.org

-- Linaro LKFT https://lkft.linaro.org