• John Johansen's avatar
    apparmor: Make path_max parameter readonly · 622f6e32
    John Johansen authored
    The path_max parameter determines the max size of buffers allocated
    but it should  not be setable at run time. If can be used to cause an
    oops
    
    root@ubuntu:~# echo 16777216 > /sys/module/apparmor/parameters/path_max
    root@ubuntu:~# cat /sys/module/apparmor/parameters/path_max
    Killed
    
    [  122.141911] BUG: unable to handle kernel paging request at ffff880080945fff
    [  122.143497] IP: [<ffffffff81228844>] d_absolute_path+0x44/0xa0
    [  122.144742] PGD 220c067 PUD 0
    [  122.145453] Oops: 0002 [#1] SMP
    [  122.146204] Modules linked in: vmw_vsock_vmci_transport vsock ppdev vmw_balloon snd_ens1371 btusb snd_ac97_codec gameport snd_rawmidi btrtl snd_seq_device ac97_bus btbcm btintel snd_pcm input_leds bluetooth snd_timer snd joydev soundcore serio_raw coretemp shpchp nfit parport_pc i2c_piix4 8250_fintek vmw_vmci parport mac_hid ib_iser rdma_cm iw_cm ib_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd vmwgfx psmouse mptspi ttm mptscsih drm_kms_helper mptbase syscopyarea scsi_transport_spi sysfillrect
    [  122.163365]  ahci sysimgblt e1000 fb_sys_fops libahci drm pata_acpi fjes
    [  122.164747] CPU: 3 PID: 1501 Comm: bash Not tainted 4.4.0-59-generic #80-Ubuntu
    [  122.166250] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
    [  122.168611] task: ffff88003496aa00 ti: ffff880076474000 task.ti: ffff880076474000
    [  122.170018] RIP: 0010:[<ffffffff81228844>]  [<ffffffff81228844>] d_absolute_path+0x44/0xa0
    [  122.171525] RSP: 0018:ffff880076477b90  EFLAGS: 00010206
    [  122.172462] RAX: ffff880080945fff RBX: 0000000000000000 RCX: 0000000001000000
    [  122.173709] RDX: 0000000000ffffff RSI: ffff880080946000 RDI: ffff8800348a1010
    [  122.174978] RBP: ffff880076477bb8 R08: ffff880076477c80 R09: 0000000000000000
    [  122.176227] R10: 00007ffffffff000 R11: ffff88007f946000 R12: ffff88007f946000
    [  122.177496] R13: ffff880076477c80 R14: ffff8800348a1010 R15: ffff8800348a2400
    [  122.178745] FS:  00007fd459eb4700(0000) GS:ffff88007b6c0000(0000) knlGS:0000000000000000
    [  122.180176] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    [  122.181186] CR2: ffff880080945fff CR3: 0000000073422000 CR4: 00000000001406e0
    [  122.182469] Stack:
    [  122.182843]  00ffffff00000001 ffff880080946000 0000000000000000 0000000000000000
    [  122.184409]  00000000570f789c ffff880076477c30 ffffffff81385671 ffff88007a2e7a58
    [  122.185810]  0000000000000000 ffff880076477c88 01000000008a1000 0000000000000000
    [  122.187231] Call Trace:
    [  122.187680]  [<ffffffff81385671>] aa_path_name+0x81/0x370
    [  122.188637]  [<ffffffff813875dd>] profile_transition+0xbd/0xb80
    [  122.190181]  [<ffffffff811af9bc>] ? zone_statistics+0x7c/0xa0
    [  122.191674]  [<ffffffff81389b20>] apparmor_bprm_set_creds+0x9b0/0xac0
    [  122.193288]  [<ffffffff812e1971>] ? ext4_xattr_get+0x81/0x220
    [  122.194793]  [<ffffffff812e800c>] ? ext4_xattr_security_get+0x1c/0x30
    [  122.196392]  [<ffffffff813449b9>] ? get_vfs_caps_from_disk+0x69/0x110
    [  122.198004]  [<ffffffff81232d4f>] ? mnt_may_suid+0x3f/0x50
    [  122.199737]  [<ffffffff81344b03>] ? cap_bprm_set_creds+0xa3/0x600
    [  122.201377]  [<ffffffff81346e53>] security_bprm_set_creds+0x33/0x50
    [  122.203024]  [<ffffffff81214ce5>] prepare_binprm+0x85/0x190
    [  122.204515]  [<ffffffff81216545>] do_execveat_common.isra.33+0x485/0x710
    [  122.206200]  [<ffffffff81216a6a>] SyS_execve+0x3a/0x50
    [  122.207615]  [<ffffffff81838795>] stub_execve+0x5/0x5
    [  122.208978]  [<ffffffff818384f2>] ? entry_SYSCALL_64_fastpath+0x16/0x71
    [  122.210615] Code: f8 31 c0 48 63 c2 83 ea 01 48 c7 45 e8 00 00 00 00 48 01 c6 85 d2 48 c7 45 f0 00 00 00 00 48 89 75 e0 89 55 dc 78 0c 48 8d 46 ff <c6> 46 ff 00 48 89 45 e0 48 8d 55 e0 48 8d 4d dc 48 8d 75 e8 e8
    [  122.217320] RIP  [<ffffffff81228844>] d_absolute_path+0x44/0xa0
    [  122.218860]  RSP <ffff880076477b90>
    [  122.219919] CR2: ffff880080945fff
    [  122.220936] ---[ end trace 506cdbd85eb6c55e ]---
    Reported-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
    Signed-off-by: default avatarJohn Johansen <john.johansen@canonical.com>
    Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
    622f6e32
lsm.c 26.6 KB