| Message ID | 20180320082714.9716-1-pvorel@suse.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2018-03-20 at 09:27 +0100, Petr Vorel wrote: > IMA requires have it's hash algorithm to be compiled-in due it's early > use. Default IMA algorithm is protected by Kconfig to be compiled-in. > > ima_hash kernel parameter allows to choose hash algorithm. When > specified algorithm not available or available as module, IMA > initialization fails, which leads to kernel panic (mknodat syscall calls > ima_post_path_mknod()). Therefore as fallback we force IMA to use > the default builtin Kconfig hash algorithm. > > $ grep CONFIG_CRYPTO_MD4 .config > CONFIG_CRYPTO_MD4=m > > [ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.12.14-2.3-default root=UUID=74ae8202-9ca7-4e39-813b-22287ec52f7a video=1024x768-16 plymouth.ignore-serial-consoles console=ttyS0 console=tty resume=/dev/disk/by-path/pci-0000:00:07.0-part3 splash=silent showopts ima_hash=md4 > ... > [ 1.545190] ima: Can not allocate md4 (reason: -2) > ... > [ 2.610120] BUG: unable to handle kernel NULL pointer dereference at (null) > [ 2.611903] IP: ima_match_policy+0x23/0x390 > [ 2.612967] PGD 0 P4D 0 > [ 2.613080] Oops: 0000 [#1] SMP > [ 2.613080] Modules linked in: autofs4 > [ 2.613080] Supported: Yes > [ 2.613080] CPU: 0 PID: 1 Comm: systemd Not tainted 4.12.14-2.3-default #1 > [ 2.613080] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 > [ 2.613080] task: ffff88003e2d0040 task.stack: ffffc90000190000 > [ 2.613080] RIP: 0010:ima_match_policy+0x23/0x390 > [ 2.613080] RSP: 0018:ffffc90000193e88 EFLAGS: 00010296 > [ 2.613080] RAX: 0000000000000000 RBX: 000000000000000c RCX: 0000000000000004 > [ 2.613080] RDX: 0000000000000010 RSI: 0000000000000001 RDI: ffff880037071728 > [ 2.613080] RBP: 0000000000008000 R08: 0000000000000000 R09: 0000000000000000 > [ 2.613080] R10: 0000000000000008 R11: 61c8864680b583eb R12: 00005580ff10086f > [ 2.613080] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000008000 > [ 2.613080] FS: 00007f5c1da08940(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000 > [ 2.613080] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 2.613080] CR2: 0000000000000000 CR3: 0000000037002000 CR4: 00000000003406f0 > [ 2.613080] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 2.613080] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 2.613080] Call Trace: > [ 2.613080] ? shmem_mknod+0xbf/0xd0 > [ 2.613080] ima_post_path_mknod+0x1c/0x40 > [ 2.613080] SyS_mknod+0x210/0x220 > [ 2.613080] entry_SYSCALL_64_fastpath+0x1a/0xa5 > [ 2.613080] RIP: 0033:0x7f5c1bfde570 > [ 2.613080] RSP: 002b:00007ffde1c90dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 > [ 2.613080] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c1bfde570 > [ 2.613080] RDX: 0000000000000000 RSI: 0000000000008000 RDI: 00005580ff10086f > [ 2.613080] RBP: 00007ffde1c91040 R08: 00005580ff10086f R09: 0000000000000000 > [ 2.613080] R10: 0000000000104000 R11: 0000000000000246 R12: 00005580ffb99660 > [ 2.613080] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 > [ 2.613080] Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 41 56 44 8d 14 09 41 55 41 54 55 53 44 89 d3 09 cb 48 83 ec 38 48 8b 05 c5 03 29 01 <4c> 8b 20 4c 39 e0 0f 84 d7 01 00 00 4c 89 44 24 08 89 54 24 20 > [ 2.613080] RIP: ima_match_policy+0x23/0x390 RSP: ffffc90000193e88 > [ 2.613080] CR2: 0000000000000000 > [ 2.613080] ---[ end trace 9a9f0a8a73079f6a ]--- > [ 2.673052] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 > [ 2.673052] > [ 2.675337] Kernel Offset: disabled > [ 2.676405] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 > > Signed-off-by: Petr Vorel <pvorel@suse.cz> > --- > security/integrity/ima/ima_main.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index 5d122daf5c8a..6ca69ab61be2 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -504,6 +504,14 @@ static int __init init_ima(void) > ima_init_template_list(); > hash_setup(CONFIG_IMA_DEFAULT_HASH); > error = ima_init(); > + > + if (error && strcmp(hash_algo_name[ima_hash_algo], > + CONFIG_IMA_DEFAULT_HASH) != 0) { > + hash_setup_done = 0; > + hash_setup(CONFIG_IMA_DEFAULT_HASH); > + error = ima_init(); > + } > + The first call to ima_init() emits an error, but we continue without any further messages. If the change was in ima_init_crypto(), the error message could indicate the resolution. Mimi > if (!error) { > ima_initialized = 1; > ima_update_policy_flag();
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 5d122daf5c8a..6ca69ab61be2 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -504,6 +504,14 @@ static int __init init_ima(void) ima_init_template_list(); hash_setup(CONFIG_IMA_DEFAULT_HASH); error = ima_init(); + + if (error && strcmp(hash_algo_name[ima_hash_algo], + CONFIG_IMA_DEFAULT_HASH) != 0) { + hash_setup_done = 0; + hash_setup(CONFIG_IMA_DEFAULT_HASH); + error = ima_init(); + } + if (!error) { ima_initialized = 1; ima_update_policy_flag();
IMA requires have it's hash algorithm to be compiled-in due it's early use. Default IMA algorithm is protected by Kconfig to be compiled-in. ima_hash kernel parameter allows to choose hash algorithm. When specified algorithm not available or available as module, IMA initialization fails, which leads to kernel panic (mknodat syscall calls ima_post_path_mknod()). Therefore as fallback we force IMA to use the default builtin Kconfig hash algorithm. $ grep CONFIG_CRYPTO_MD4 .config CONFIG_CRYPTO_MD4=m [ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.12.14-2.3-default root=UUID=74ae8202-9ca7-4e39-813b-22287ec52f7a video=1024x768-16 plymouth.ignore-serial-consoles console=ttyS0 console=tty resume=/dev/disk/by-path/pci-0000:00:07.0-part3 splash=silent showopts ima_hash=md4 ... [ 1.545190] ima: Can not allocate md4 (reason: -2) ... [ 2.610120] BUG: unable to handle kernel NULL pointer dereference at (null) [ 2.611903] IP: ima_match_policy+0x23/0x390 [ 2.612967] PGD 0 P4D 0 [ 2.613080] Oops: 0000 [#1] SMP [ 2.613080] Modules linked in: autofs4 [ 2.613080] Supported: Yes [ 2.613080] CPU: 0 PID: 1 Comm: systemd Not tainted 4.12.14-2.3-default #1 [ 2.613080] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 [ 2.613080] task: ffff88003e2d0040 task.stack: ffffc90000190000 [ 2.613080] RIP: 0010:ima_match_policy+0x23/0x390 [ 2.613080] RSP: 0018:ffffc90000193e88 EFLAGS: 00010296 [ 2.613080] RAX: 0000000000000000 RBX: 000000000000000c RCX: 0000000000000004 [ 2.613080] RDX: 0000000000000010 RSI: 0000000000000001 RDI: ffff880037071728 [ 2.613080] RBP: 0000000000008000 R08: 0000000000000000 R09: 0000000000000000 [ 2.613080] R10: 0000000000000008 R11: 61c8864680b583eb R12: 00005580ff10086f [ 2.613080] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000008000 [ 2.613080] FS: 00007f5c1da08940(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000 [ 2.613080] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.613080] CR2: 0000000000000000 CR3: 0000000037002000 CR4: 00000000003406f0 [ 2.613080] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2.613080] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2.613080] Call Trace: [ 2.613080] ? shmem_mknod+0xbf/0xd0 [ 2.613080] ima_post_path_mknod+0x1c/0x40 [ 2.613080] SyS_mknod+0x210/0x220 [ 2.613080] entry_SYSCALL_64_fastpath+0x1a/0xa5 [ 2.613080] RIP: 0033:0x7f5c1bfde570 [ 2.613080] RSP: 002b:00007ffde1c90dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 [ 2.613080] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c1bfde570 [ 2.613080] RDX: 0000000000000000 RSI: 0000000000008000 RDI: 00005580ff10086f [ 2.613080] RBP: 00007ffde1c91040 R08: 00005580ff10086f R09: 0000000000000000 [ 2.613080] R10: 0000000000104000 R11: 0000000000000246 R12: 00005580ffb99660 [ 2.613080] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 [ 2.613080] Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 41 56 44 8d 14 09 41 55 41 54 55 53 44 89 d3 09 cb 48 83 ec 38 48 8b 05 c5 03 29 01 <4c> 8b 20 4c 39 e0 0f 84 d7 01 00 00 4c 89 44 24 08 89 54 24 20 [ 2.613080] RIP: ima_match_policy+0x23/0x390 RSP: ffffc90000193e88 [ 2.613080] CR2: 0000000000000000 [ 2.613080] ---[ end trace 9a9f0a8a73079f6a ]--- [ 2.673052] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 [ 2.673052] [ 2.675337] Kernel Offset: disabled [ 2.676405] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 Signed-off-by: Petr Vorel <pvorel@suse.cz> --- security/integrity/ima/ima_main.c | 8 ++++++++ 1 file changed, 8 insertions(+)