Dave Wysochanski e4a7d1f770 SUNRPC: Handle 0 length opaque XDR object data properly ... When handling an auth_gss downcall, it's possible to get 0-length opaque object for the acceptor. In the case of a 0-length XDR object, make sure simple_get_netobj() fills in dest->data = NULL, and does not continue to kmemdup() which will set dest->data = ZERO_SIZE_PTR for the acceptor. The trace event code can handle NULL but not ZERO_SIZE_PTR for a string, and so without this patch the rpcgss_context trace event will crash the kernel as follows: [ 162.887992] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 162.898693] #PF: supervisor read access in kernel mode [ 162.900830] #PF: error_code(0x0000) - not-present page [ 162.902940] PGD 0 P4D 0 [ 162.904027] Oops: 0000 [#1] SMP PTI [ 162.905493] CPU: 4 PID: 4321 Comm: rpc.gssd Kdump: loaded Not tainted 5.10.0 #133 [ 162.908548] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [ 162.910978] RIP: 0010:strlen+0x0/0x20 [ 162.912505] Code: 48 89 f9 74 09 48 83 c1 01 80 39 00 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee c3 0f 1f 80 00 00 00 00 <80> 3f 00 74 10 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 31 [ 162.920101] RSP: 0018:ffffaec900c77d90 EFLAGS: 00010202 [ 162.922263] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000fffde697 [ 162.925158] RDX: 000000000000002f RSI: 0000000000000080 RDI: 0000000000000010 [ 162.928073] RBP: 0000000000000010 R08: 0000000000000e10 R09: 0000000000000000 [ 162.930976] R10: ffff8e698a590cb8 R11: 0000000000000001 R12: 0000000000000e10 [ 162.933883] R13: 00000000fffde697 R14: 000000010034d517 R15: 0000000000070028 [ 162.936777] FS: 00007f1e1eb93700(0000) GS:ffff8e6ab7d00000(0000) knlGS:0000000000000000 [ 162.940067] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 162.942417] CR2: 0000000000000010 CR3: 0000000104eba000 CR4: 00000000000406e0 [ 162.945300] Call Trace: [ 162.946428] trace_event_raw_event_rpcgss_context+0x84/0x140 [auth_rpcgss] [ 162.949308] ? __kmalloc_track_caller+0x35/0x5a0 [ 162.951224] ? gss_pipe_downcall+0x3a3/0x6a0 [auth_rpcgss] [ 162.953484] gss_pipe_downcall+0x585/0x6a0 [auth_rpcgss] [ 162.955953] rpc_pipe_write+0x58/0x70 [sunrpc] [ 162.957849] vfs_write+0xcb/0x2c0 [ 162.959264] ksys_write+0x68/0xe0 [ 162.960706] do_syscall_64+0x33/0x40 [ 162.962238] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 162.964346] RIP: 0033:0x7f1e1f1e57df Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>		2021-01-25 15:59:12 -05:00
..
Makefile	SUNRPC: Introduce trace points in rpc_auth_gss.ko	2019-02-14 09:20:40 -05:00
auth_gss.c	SUNRPC: Move simple_get_bytes and simple_get_netobj into private header	2021-01-25 15:59:12 -05:00
auth_gss_internal.h	SUNRPC: Handle 0 length opaque XDR object data properly	2021-01-25 15:59:12 -05:00
gss_generic_token.c	sunrpc: whitespace fixes	2018-07-31 12:53:40 -04:00
gss_krb5_crypto.c	SUNRPC: remove RC4-HMAC-MD5 support from KerberosV	2020-09-11 14:39:15 +10:00
gss_krb5_keys.c	mm, treewide: rename kzfree() to kfree_sensitive()	2020-08-07 11:33:22 -07:00
gss_krb5_mech.c	SUNRPC: Move simple_get_bytes and simple_get_netobj into private header	2021-01-25 15:59:12 -05:00
gss_krb5_seal.c	SUNRPC: remove RC4-HMAC-MD5 support from KerberosV	2020-09-11 14:39:15 +10:00
gss_krb5_seqnum.c	SUNRPC: remove RC4-HMAC-MD5 support from KerberosV	2020-09-11 14:39:15 +10:00
gss_krb5_unseal.c	SUNRPC: remove RC4-HMAC-MD5 support from KerberosV	2020-09-11 14:39:15 +10:00
gss_krb5_wrap.c	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2020-10-13 08:50:16 -07:00
gss_mech_switch.c	sunrpc: clean up properly in gss_mech_unregister()	2020-05-28 18:15:00 -04:00
gss_rpc_upcall.c	SUNRPC: Remove XDRBUF_SPARSE_PAGES flag in gss_proxy upcall	2020-12-09 09:38:34 -05:00
gss_rpc_upcall.h	SUNRPC: Add SPDX IDs to some net/sunrpc/auth_gss/ files	2019-02-14 09:54:37 -05:00
gss_rpc_xdr.c	SUNRPC: Remove XDRBUF_SPARSE_PAGES flag in gss_proxy upcall	2020-12-09 09:38:34 -05:00
gss_rpc_xdr.h	SUNRPC: Add SPDX IDs to some net/sunrpc/auth_gss/ files	2019-02-14 09:54:37 -05:00
svcauth_gss.c	SUNRPC: fix copying of multiple pages in gss_read_proxy_verf()	2020-10-20 13:21:30 -04:00
trace.c	SUNRPC: remove duplicate include	2020-08-19 13:19:42 -04:00