Hi Chuck
On Sun, Jan 15, 2023 at 12:23 PM Chuck Lever cel@kernel.org wrote:
From: Chuck Lever chuck.lever@oracle.com
Fill in entries in the supported_gss_krb5_enctypes array for the encryption types defined in RFC 8009. These new enctypes use the SHA-256 and SHA-384 message digest algorithms (as defined in FIPS-180) instead of the deprecated SHA-1 algorithm, and are thus more secure.
Note that NIST has scheduled SHA-1 for deprecation:
https://www.nist.gov/news-events/news/2022/12/nist-retires-sha-1-cryptograph...
Thus these new encryption types are placed under a separate CONFIG option to enable distributors to separately introduce support for the AES-SHA2 enctypes and deprecate support for the current set of AES-SHA1 encryption types as their user space allows.
As this implementation is still a "beta", the default is to not build it automatically.
Tested-by: Scott Mayhew smayhew@redhat.com Signed-off-by: Chuck Lever chuck.lever@oracle.com
include/linux/sunrpc/gss_krb5.h | 19 ++++++++++++- net/sunrpc/Kconfig | 14 ++++++++++ net/sunrpc/auth_gss/gss_krb5_mech.c | 51 +++++++++++++++++++++++++++++++++++ 3 files changed, 82 insertions(+), 2 deletions(-)
diff --git a/include/linux/sunrpc/gss_krb5.h b/include/linux/sunrpc/gss_krb5.h index 3e97d2a7c87d..8ff397b5c04b 100644 --- a/include/linux/sunrpc/gss_krb5.h +++ b/include/linux/sunrpc/gss_krb5.h @@ -54,8 +54,8 @@ /* Maximum key length (in bytes) for the supported crypto algorithms */ #define GSS_KRB5_MAX_KEYLEN (32)
-/* Maximum checksum function output for the supported crypto algorithms */ -#define GSS_KRB5_MAX_CKSUM_LEN (20) +/* Maximum checksum function output for the supported enctypes */ +#define GSS_KRB5_MAX_CKSUM_LEN (24)
I'm having some problems that I bisected to this patch, specifically this change to GSS_KRB5_MAX_CKSUM_LEN. KASAN reports it as a slab-out-of-bounds in gss_krb5_checksum(), and it can cause my client to panic when running cthon basic tests with krb5p. I was wondering if you've seen this?
Anna
Here is what kasan tells me:
[ 35.725366] ================================================================== [ 35.725373] BUG: KASAN: slab-out-of-bounds in gss_krb5_checksum+0x4b6/0x630 [rpcsec_gss_krb5] [ 35.725383] Read of size 24 at addr ffff888110cfc1a0 by task mount.nfs/853
[ 35.725390] CPU: 2 PID: 853 Comm: mount.nfs Not tainted 6.2.0-ga40cf7530d31+ #37820 4b7d53453529728aac4e973d4ba6a17952148f02 [ 35.725395] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [ 35.725399] Call Trace: [ 35.725401] <TASK> [ 35.725404] dump_stack_lvl+0x48/0x60 [ 35.725409] print_report+0x184/0x4a8 [ 35.725414] ? memcpy+0x3c/0x60 [ 35.725419] ? gss_krb5_checksum+0x4b6/0x630 [rpcsec_gss_krb5 2fd8c249acfdf3162b23b30d5eb7af0425d84960] [ 35.725426] kasan_report+0xc9/0x150 [ 35.725431] ? gss_krb5_checksum+0x4b6/0x630 [rpcsec_gss_krb5 2fd8c249acfdf3162b23b30d5eb7af0425d84960] [ 35.725439] kasan_check_range+0x13e/0x1c0 [ 35.725447] memcpy+0x23/0x60 [ 35.725451] gss_krb5_checksum+0x4b6/0x630 [rpcsec_gss_krb5 2fd8c249acfdf3162b23b30d5eb7af0425d84960] [ 35.725460] ? __pfx_gss_krb5_checksum+0x10/0x10 [rpcsec_gss_krb5 2fd8c249acfdf3162b23b30d5eb7af0425d84960] [ 35.725467] ? memmove+0x3c/0x60 [ 35.725472] gss_krb5_aes_encrypt+0x388/0x7c0 [rpcsec_gss_krb5 2fd8c249acfdf3162b23b30d5eb7af0425d84960] [ 35.725480] ? __pfx_gss_krb5_aes_encrypt+0x10/0x10 [rpcsec_gss_krb5 2fd8c249acfdf3162b23b30d5eb7af0425d84960] [ 35.725487] ? memmove+0x3c/0x60 [ 35.725491] gss_krb5_wrap_v2+0x28e/0x3a0 [rpcsec_gss_krb5 2fd8c249acfdf3162b23b30d5eb7af0425d84960] [ 35.725500] gss_wrap_req_priv+0x3d7/0x1090 [auth_rpcgss 9532107bdb7719d1a30fdcf239028e9e54e0c27c] [ 35.725517] gss_wrap_req+0x1df/0x250 [auth_rpcgss 9532107bdb7719d1a30fdcf239028e9e54e0c27c] [ 35.725572] call_encode+0x75a/0x1000 [sunrpc 807a235f89c5b6b32dbda9261e96d6b1ac9ed4f5] [ 35.725626] ? __pfx_call_encode+0x10/0x10 [sunrpc 807a235f89c5b6b32dbda9261e96d6b1ac9ed4f5] [ 35.725671] ? __kasan_kmalloc+0xad/0xb0 [ 35.725676] ? xprt_alloc_slot+0x1ca/0x590 [sunrpc 807a235f89c5b6b32dbda9261e96d6b1ac9ed4f5] [ 35.725724] ? call_allocate+0x30d/0x6b0 [sunrpc 807a235f89c5b6b32dbda9261e96d6b1ac9ed4f5] [ 35.725779] ? __pfx_call_encode+0x10/0x10 [sunrpc 807a235f89c5b6b32dbda9261e96d6b1ac9ed4f5] [ 35.725829] __rpc_execute+0x29b/0xcf0 [sunrpc 807a235f89c5b6b32dbda9261e96d6b1ac9ed4f5] [ 35.725885] ? __pfx___rpc_execute+0x10/0x10 [sunrpc 807a235f89c5b6b32dbda9261e96d6b1ac9ed4f5] [ 35.725936] ? __pfx_wake_up_bit+0x10/0x10 [ 35.725941] ? _raw_spin_lock+0x85/0xe0 [ 35.725945] rpc_execute+0x21d/0x320 [sunrpc 807a235f89c5b6b32dbda9261e96d6b1ac9ed4f5] [ 35.725997] rpc_run_task+0x467/0x650 [sunrpc 807a235f89c5b6b32dbda9261e96d6b1ac9ed4f5] [ 35.726044] nfs4_call_sync_sequence+0x17e/0x2a0 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726095] ? unwind_get_return_address+0x5e/0xa0 [ 35.726100] ? __pfx_nfs4_call_sync_sequence+0x10/0x10 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726146] ? stack_trace_save+0x95/0xd0 [ 35.726151] ? __stack_depot_save+0x3f/0x4c0 [ 35.726157] _nfs4_lookup_root.isra.0+0x193/0x200 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726202] ? __pfx__nfs4_lookup_root.isra.0+0x10/0x10 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726246] ? kasan_save_stack+0x45/0x60 [ 35.726251] ? nfs_alloc_fattr+0x44/0x210 [nfs 1894ec9cbdec354be2bcab1be6e5e8ab9f92de62] [ 35.726290] ? nfs4_get_rootfh+0x92/0x290 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726341] ? nfs4_server_common_setup+0xa4/0x680 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726391] ? nfs4_create_server+0x8d7/0xf00 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726440] ? nfs4_try_get_tree+0xd1/0x250 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726488] ? entry_SYSCALL_64_after_hwframe+0x72/0xdc [ 35.726496] nfs4_lookup_root+0xeb/0x260 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726542] ? __pfx_nfs4_lookup_root+0x10/0x10 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726589] nfs4_proc_get_rootfh+0xdc/0x110 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726636] nfs4_get_rootfh+0xb4/0x290 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726685] ? __pfx_nfs4_get_rootfh+0x10/0x10 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726733] ? nfs4_set_client+0x2d8/0x430 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726785] nfs4_server_common_setup+0xa4/0x680 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726834] nfs4_create_server+0x8d7/0xf00 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726884] ? _raw_spin_lock+0x85/0xe0 [ 35.726888] ? __pfx_nfs4_create_server+0x10/0x10 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726937] ? __module_get+0x31/0xf0 [ 35.726942] nfs4_try_get_tree+0xd1/0x250 [nfsv4 d67fe18359c6743dcd6788d44186185ed97423ee] [ 35.726991] vfs_get_tree+0x84/0x2c0 [ 35.726996] path_mount+0xa9f/0x1a20 [ 35.727001] ? __pfx_path_mount+0x10/0x10 [ 35.727005] ? user_path_at_empty+0x44/0x60 [ 35.727008] ? kmem_cache_free+0x19e/0x320 [ 35.727013] __x64_sys_mount+0x214/0x280 [ 35.727017] ? __pfx___x64_sys_mount+0x10/0x10 [ 35.727020] ? _raw_spin_lock+0x85/0xe0 [ 35.727024] do_syscall_64+0x5c/0x90 [ 35.727029] ? syscall_exit_to_user_mode+0x1b/0x40 [ 35.727032] ? do_syscall_64+0x6b/0x90 [ 35.727036] entry_SYSCALL_64_after_hwframe+0x72/0xdc [ 35.727040] RIP: 0033:0x7f1291a5afde [ 35.727044] Code: 48 8b 0d 95 ed 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 62 ed 0c 00 f7 d8 64 89 01 48 [ 35.727047] RSP: 002b:00007ffd02e479e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 35.727055] RAX: ffffffffffffffda RBX: 00007ffd02e47b90 RCX: 00007f1291a5afde [ 35.727058] RDX: 00005565e507c3b0 RSI: 00005565e507b500 RDI: 00005565e507b550 [ 35.727060] RBP: 00005565e50824f0 R08: 00005565e50824f0 R09: 0000000000000060 [ 35.727062] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd02e47b90 [ 35.727065] R13: 00005565e5082210 R14: 0000000000000003 R15: 00005565e42168f8 [ 35.727069] </TASK>
[ 35.727073] Allocated by task 853: [ 35.727075] kasan_save_stack+0x33/0x60 [ 35.727079] kasan_set_track+0x25/0x30 [ 35.727082] __kasan_kmalloc+0xad/0xb0 [ 35.727086] __kmalloc+0x5e/0x160 [ 35.727088] gss_krb5_checksum+0xcf/0x630 [rpcsec_gss_krb5] [ 35.727095] gss_krb5_aes_encrypt+0x388/0x7c0 [rpcsec_gss_krb5] [ 35.727101] gss_krb5_wrap_v2+0x28e/0x3a0 [rpcsec_gss_krb5] [ 35.727107] gss_wrap_req_priv+0x3d7/0x1090 [auth_rpcgss] [ 35.727119] gss_wrap_req+0x1df/0x250 [auth_rpcgss] [ 35.727131] call_encode+0x75a/0x1000 [sunrpc] [ 35.727175] __rpc_execute+0x29b/0xcf0 [sunrpc] [ 35.727227] rpc_execute+0x21d/0x320 [sunrpc] [ 35.727277] rpc_run_task+0x467/0x650 [sunrpc] [ 35.727321] nfs4_call_sync_sequence+0x17e/0x2a0 [nfsv4] [ 35.727365] _nfs4_lookup_root.isra.0+0x193/0x200 [nfsv4] [ 35.727408] nfs4_lookup_root+0xeb/0x260 [nfsv4] [ 35.727453] nfs4_proc_get_rootfh+0xdc/0x110 [nfsv4] [ 35.727498] nfs4_get_rootfh+0xb4/0x290 [nfsv4] [ 35.727546] nfs4_server_common_setup+0xa4/0x680 [nfsv4] [ 35.727595] nfs4_create_server+0x8d7/0xf00 [nfsv4] [ 35.727643] nfs4_try_get_tree+0xd1/0x250 [nfsv4] [ 35.727690] vfs_get_tree+0x84/0x2c0 [ 35.727694] path_mount+0xa9f/0x1a20 [ 35.727697] __x64_sys_mount+0x214/0x280 [ 35.727701] do_syscall_64+0x5c/0x90 [ 35.727704] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[ 35.727709] The buggy address belongs to the object at ffff888110cfc1a0 which belongs to the cache kmalloc-32 of size 32 [ 35.727712] The buggy address is located 0 bytes inside of 32-byte region [ffff888110cfc1a0, ffff888110cfc1c0)
[ 35.727717] The buggy address belongs to the physical page: [ 35.727721] page:ffffea0004433f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888110cfce60 pfn:0x110cfc [ 35.727726] flags: 0x2ffff0000000200(slab|node=0|zone=2|lastcpupid=0xffff) [ 35.727731] raw: 02ffff0000000200 ffff888100042740 ffffea00044274d0 ffff888100040450 [ 35.727734] raw: ffff888110cfce60 0000000000150012 00000001ffffffff 0000000000000000 [ 35.727736] page dumped because: kasan: bad access detected [ 35.727740] page_owner tracks the page as allocated [ 35.727741] page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 715, tgid 715 (test2), ts 24589446140, free_ts 24535345796 [ 35.727747] post_alloc_hook+0x118/0x250 [ 35.727750] get_page_from_freelist+0x11ef/0x3a20 [ 35.727754] __alloc_pages+0x1d5/0x440 [ 35.727757] allocate_slab+0x346/0x4a0 [ 35.727760] ___slab_alloc+0x39a/0x9a0 [ 35.727763] __kmem_cache_alloc_node+0x143/0x3d0 [ 35.727766] __kmalloc+0x4d/0x160 [ 35.727768] gss_krb5_checksum+0xcf/0x630 [rpcsec_gss_krb5] [ 35.727775] gss_krb5_verify_mic_v2+0x2d2/0x4f0 [rpcsec_gss_krb5] [ 35.727780] gss_validate+0x360/0x700 [auth_rpcgss] [ 35.727792] rpc_decode_header+0x288/0xcb0 [sunrpc] [ 35.727836] call_decode+0x3a7/0x780 [sunrpc] [ 35.727880] __rpc_execute+0x29b/0xcf0 [sunrpc] [ 35.727932] rpc_execute+0x21d/0x320 [sunrpc] [ 35.727982] rpc_run_task+0x467/0x650 [sunrpc] [ 35.728026] nfs4_call_sync_sequence+0x17e/0x2a0 [nfsv4] [ 35.728070] page last free stack trace: [ 35.728072] free_pcp_prepare+0x66c/0x10e0 [ 35.728075] free_unref_page+0x4e/0x3c0 [ 35.728078] tlb_remove_table_rcu+0x77/0xc0 [ 35.728081] rcu_do_batch+0x34c/0xd00 [ 35.728084] rcu_core+0x447/0xf20 [ 35.728086] __do_softirq+0x1d6/0x5ed
[ 35.728091] Memory state around the buggy address: [ 35.728093] ffff888110cfc080: fc fc fc fc fc fc fc fc fc fc fc fc fa fb fb fb [ 35.728096] ffff888110cfc100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 35.728098] >ffff888110cfc180: fc fc fc fc 00 00 04 fc fc fc fc fc fc fc fc fc [ 35.728100] ^ [ 35.728102] ffff888110cfc200: fc fc fc fc fc fc fc fc fc fc fc fc 00 00 00 00 [ 35.728104] ffff888110cfc280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 35.728106] ==================================================================
/* Maximum blocksize for the supported crypto algorithms */ #define GSS_KRB5_MAX_BLOCKSIZE (16) @@ -160,6 +160,12 @@ enum seal_alg { SEAL_ALG_DES3KD = 0x0002 };
+/*
- These values are assigned by IANA and published via the
- subregistry at the link below:
- */
#define CKSUMTYPE_CRC32 0x0001 #define CKSUMTYPE_RSA_MD4 0x0002 #define CKSUMTYPE_RSA_MD4_DES 0x0003 @@ -170,6 +176,8 @@ enum seal_alg { #define CKSUMTYPE_HMAC_SHA1_DES3 0x000c #define CKSUMTYPE_HMAC_SHA1_96_AES128 0x000f #define CKSUMTYPE_HMAC_SHA1_96_AES256 0x0010 +#define CKSUMTYPE_HMAC_SHA256_128_AES128 0x0013 +#define CKSUMTYPE_HMAC_SHA384_192_AES256 0x0014 #define CKSUMTYPE_HMAC_MD5_ARCFOUR -138 /* Microsoft md5 hmac cksumtype */
/* from gssapi_err_krb5.h */ @@ -190,6 +198,11 @@ enum seal_alg {
/* per Kerberos v5 protocol spec crypto types from the wire.
- these get mapped to linux kernel crypto routines.
- These values are assigned by IANA and published via the
- subregistry at the link below:
- */
#define ENCTYPE_NULL 0x0000 #define ENCTYPE_DES_CBC_CRC 0x0001 /* DES cbc mode with CRC-32 */ @@ -203,6 +216,8 @@ enum seal_alg { #define ENCTYPE_DES3_CBC_SHA1 0x0010 #define ENCTYPE_AES128_CTS_HMAC_SHA1_96 0x0011 #define ENCTYPE_AES256_CTS_HMAC_SHA1_96 0x0012 +#define ENCTYPE_AES128_CTS_HMAC_SHA256_128 0x0013 +#define ENCTYPE_AES256_CTS_HMAC_SHA384_192 0x0014 #define ENCTYPE_ARCFOUR_HMAC 0x0017 #define ENCTYPE_ARCFOUR_HMAC_EXP 0x0018 #define ENCTYPE_UNKNOWN 0x01ff diff --git a/net/sunrpc/Kconfig b/net/sunrpc/Kconfig index 1135ff362132..b1aa2318e1dc 100644 --- a/net/sunrpc/Kconfig +++ b/net/sunrpc/Kconfig @@ -76,6 +76,20 @@ config RPCSEC_GSS_KRB5_ENCTYPES_AES_SHA1 SHA-1 digests. These include aes128-cts-hmac-sha1-96 and aes256-cts-hmac-sha1-96.
+config RPCSEC_GSS_KRB5_ENCTYPES_AES_SHA2
bool "Enable Kerberos enctypes based on AES and SHA-2"depends on RPCSEC_GSS_KRB5depends on CRYPTO_CBC && CRYPTO_CTSdepends on CRYPTO_HMAC && CRYPTO_SHA256 && CRYPTO_SHA512depends on CRYPTO_AESdefault nselect RPCSEC_GSS_KRB5_CRYPTOSYSTEMhelpChoose Y to enable the use of Kerberos 5 encryption typesthat utilize Advanced Encryption Standard (AES) ciphers andSHA-2 digests. These include aes128-cts-hmac-sha256-128 andaes256-cts-hmac-sha384-192.config SUNRPC_DEBUG bool "RPC: Enable dprintk debugging" depends on SUNRPC && SYSCTL diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c index ec3cca8fadc5..1951867f3fa8 100644 --- a/net/sunrpc/auth_gss/gss_krb5_mech.c +++ b/net/sunrpc/auth_gss/gss_krb5_mech.c @@ -146,6 +146,57 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = { .keyed_cksum = 1, }, #endif
+#if defined(CONFIG_RPCSEC_GSS_KRB5_ENCTYPES_AES_SHA2)
/** AES-128 with SHA-256 (RFC 8009)*/{.etype = ENCTYPE_AES128_CTS_HMAC_SHA256_128,.ctype = CKSUMTYPE_HMAC_SHA256_128_AES128,.name = "aes128-cts-hmac-sha256-128",.encrypt_name = "cts(cbc(aes))",.aux_cipher = "cbc(aes)",.cksum_name = "hmac(sha256)",.cksumlength = BITS2OCTETS(128),.keyed_cksum = 1,.keylength = BITS2OCTETS(128),.Kc_length = BITS2OCTETS(128),.Ke_length = BITS2OCTETS(128),.Ki_length = BITS2OCTETS(128),.import_ctx = gss_krb5_import_ctx_v2,.get_mic = gss_krb5_get_mic_v2,.verify_mic = gss_krb5_verify_mic_v2,.wrap = gss_krb5_wrap_v2,.unwrap = gss_krb5_unwrap_v2,},/** AES-256 with SHA-384 (RFC 8009)*/{.etype = ENCTYPE_AES256_CTS_HMAC_SHA384_192,.ctype = CKSUMTYPE_HMAC_SHA384_192_AES256,.name = "aes256-cts-hmac-sha384-192",.encrypt_name = "cts(cbc(aes))",.aux_cipher = "cbc(aes)",.cksum_name = "hmac(sha384)",.cksumlength = BITS2OCTETS(192),.keyed_cksum = 1,.keylength = BITS2OCTETS(256),.Kc_length = BITS2OCTETS(192),.Ke_length = BITS2OCTETS(256),.Ki_length = BITS2OCTETS(192),.import_ctx = gss_krb5_import_ctx_v2,.get_mic = gss_krb5_get_mic_v2,.verify_mic = gss_krb5_verify_mic_v2,.wrap = gss_krb5_wrap_v2,.unwrap = gss_krb5_unwrap_v2,},+#endif };
/*