On Wed, Jan 13, 2016 at 11:09 PM, Robert Święcki <robert@xxxxxxxxxxx> wrote: > Also, text/plain for the list > > Hi, there seems to be a bug in the overlay which causes a general page fault. > > To replicate I used https://github.com/google/nsjail > > I used kernel > > $ uname -a > Linux jag 4.3.0-5-generic #16-Ubuntu SMP Wed Dec 16 23:33:25 UTC 2015 > x86_64 x86_64 x86_64 GNU/Linux > > $ ./nsjail -T /tmp -Mo --chroot /chroot/ --user 0 --group 0 > --keep_caps -- /bin/sh -i > / # mkdir /tmp/h > / # mkdir /tmp/h/w > / # mkdir /tmp/h/u > / # mkdir /tmp/h/o > / # mount -t overlayfs -o > lowerdir=/bin,upperdir=/tmp/h/u,workdir=/tmp/h/w overlay /tmp/h/o > / # cd /tmp/h/o > /tmp/h/o # mv sh uuuuu > Killed > > in dmesg > > [176111.038478] overlayfs: ERROR - failed to whiteout '#ffff880004d9ff00' This seems to be a modified kernel. Was anything else changed? Thanks, Miklos > [176111.038511] BUG: unable to handle kernel paging request at ffffffffffffffff > [176111.038517] IP: [<ffffffff81218e3e>] dput+0x1e/0x220 > [176111.038527] PGD 1e0f067 PUD 1e11067 PMD 0 > [176111.038533] Oops: 0000 [#2] SMP > [176111.038537] Modules linked in: overlay nls_utf8 btrfs xor raid6_pq > ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c input_leds > pl2303 usbserial uvcvideo videobuf2_vmalloc videobuf2_memops > videobuf2_core v4l2_common videodev media snd_usb_audio > snd_usbmidi_lib pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) > vboxdrv(OE) binfmt_misc snd_hda_codec_hdmi eeepc_wmi asus_wmi > sparse_keymap video mxm_wmi snd_hda_codec_realtek > snd_hda_codec_generic nvidia(POE) snd_hda_intel snd_hda_codec > serio_raw snd_hda_core edac_mce_amd snd_hwdep fam15h_power edac_core > i2c_piix4 k10temp snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi > snd_seq snd_seq_device snd_timer drm snd soundcore shpchp wmi mac_hid > kvm_amd kvm it87 hwmon_vid parport_pc ppdev lp parport autofs4 drbg > ansi_cprng algif_skcipher af_alg dm_crypt > [176111.038613] uas usb_storage hid_generic usbhid hid > crct10dif_pclmul crc32_pclmul aesni_intel aes_x86_64 lrw gf128mul > glue_helper ablk_helper cryptd psmouse e1000e ahci ptp libahci > pps_core fjes > [176111.038637] CPU: 7 PID: 21179 Comm: busybox Tainted: P D > OE 4.3.0-5-generic #16-Ubuntu > [176111.038645] task: ffff88042b7bc600 ti: ffff8803f2fe4000 task.ti: > ffff8803f2fe4000 > [176111.038648] RIP: 0010:[<ffffffff81218e3e>] [<ffffffff81218e3e>] > dput+0x1e/0x220 > [176111.038655] RSP: 0018:ffff8803f2fe7d48 EFLAGS: 00010286 > [176111.038658] RAX: 0000000000000001 RBX: ffffffffffffffff RCX: > 0000000200000000 > [176111.038661] RDX: 0000000000000001 RSI: ffffffff81218080 RDI: > ffffffffffffffff > [176111.038664] RBP: ffff8803f2fe7d70 R08: 000000000000000a R09: > 0000000000000652 > [176111.038667] R10: 0000000000000000 R11: 0000000000000652 R12: > 0000000000000057 > [176111.038670] R13: 00000000ffffffff R14: 0000000000000000 R15: > ffff880004d9ff00 > [176111.038674] FS: 00000000022cc8c0(0063) GS:ffff88043edc0000(0000) > knlGS:00000000ef69eb40 > [176111.038677] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [176111.038679] CR2: ffffffffffffffff CR3: 000000032ff67000 CR4: > 00000000000406e0 > [176111.038682] Stack: > [176111.038685] ffff88024847e600 ffff880004d9f6c0 00000000ffffffff > 0000000000000000 > [176111.038690] ffff880004d9ff00 ffff8803f2fe7e10 ffffffffc102193e > ffffffff8120c608 > [176111.038695] 0000000000000000 0000000000000000 0000000000000000 > ffff880427b33900 > [176111.038699] Call Trace: > [176111.038711] [<ffffffffc102193e>] ovl_rename2+0x78e/0x970 [overlay] > [176111.038717] [<ffffffff8120c608>] ? __inode_permission+0x48/0xb0 > [176111.038722] [<ffffffff8120f3da>] vfs_rename+0x54a/0x870 > [176111.038729] [<ffffffff8132e000>] ? security_path_rename+0x60/0xd0 > [176111.038734] [<ffffffff8121410b>] SyS_rename+0x38b/0x3d0 > [176111.038741] [<ffffffff817fba72>] entry_SYSCALL_64_fastpath+0x16/0x71 > [176111.038744] Code: 40 00 e9 38 ff ff ff 66 0f 1f 44 00 00 0f 1f 44 > 00 00 48 85 ff 74 4e 55 48 89 e5 41 57 41 56 41 55 41 54 4c 8d 67 58 > 53 48 89 fb <f6> 03 08 4c 89 e7 0f 85 86 00 00 00 e8 e1 7e 1c 00 85 c0 > 0f 88 > [176111.038794] RIP [<ffffffff81218e3e>] dput+0x1e/0x220 > [176111.038800] RSP <ffff8803f2fe7d48> > [176111.038802] CR2: ffffffffffffffff > [176111.038807] ---[ end trace b0f2f36c0da5e3f8 ]--- > > > -- > Robert Święcki -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
