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authorXiaolong Huang <butterflyhuangxx@gmail.com>2022-03-30 15:22:14 +0100
committerPaolo Abeni <pabeni@redhat.com>2022-03-31 15:21:31 +0200
commitff8376ade4f668130385839cef586a0990f8ef87 (patch)
tree228d8cf11d68637b84d92813179bb93787909160 /net
parent4a7f62f91933c8ae5308f9127fd8ea48188b6bc3 (diff)
downloadlinux-ff8376ade4f668130385839cef586a0990f8ef87.tar.bz2
rxrpc: fix some null-ptr-deref bugs in server_key.c
Some function calls are not implemented in rxrpc_no_security, there are preparse_server_key, free_preparse_server_key and destroy_server_key. When rxrpc security type is rxrpc_no_security, user can easily trigger a null-ptr-deref bug via ioctl. So judgment should be added to prevent it The crash log: user@syzkaller:~$ ./rxrpc_preparse_s [ 37.956878][T15626] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 37.957645][T15626] #PF: supervisor instruction fetch in kernel mode [ 37.958229][T15626] #PF: error_code(0x0010) - not-present page [ 37.958762][T15626] PGD 4aadf067 P4D 4aadf067 PUD 4aade067 PMD 0 [ 37.959321][T15626] Oops: 0010 [#1] PREEMPT SMP [ 37.959739][T15626] CPU: 0 PID: 15626 Comm: rxrpc_preparse_ Not tainted 5.17.0-01442-gb47d5a4f6b8d #43 [ 37.960588][T15626] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014 [ 37.961474][T15626] RIP: 0010:0x0 [ 37.961787][T15626] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. [ 37.962480][T15626] RSP: 0018:ffffc9000d9abdc0 EFLAGS: 00010286 [ 37.963018][T15626] RAX: ffffffff84335200 RBX: ffff888012a1ce80 RCX: 0000000000000000 [ 37.963727][T15626] RDX: 0000000000000000 RSI: ffffffff84a736dc RDI: ffffc9000d9abe48 [ 37.964425][T15626] RBP: ffffc9000d9abe48 R08: 0000000000000000 R09: 0000000000000002 [ 37.965118][T15626] R10: 000000000000000a R11: f000000000000000 R12: ffff888013145680 [ 37.965836][T15626] R13: 0000000000000000 R14: ffffffffffffffec R15: ffff8880432aba80 [ 37.966441][T15626] FS: 00007f2177907700(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000 [ 37.966979][T15626] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 37.967384][T15626] CR2: ffffffffffffffd6 CR3: 000000004aaf1000 CR4: 00000000000006f0 [ 37.967864][T15626] Call Trace: [ 37.968062][T15626] <TASK> [ 37.968240][T15626] rxrpc_preparse_s+0x59/0x90 [ 37.968541][T15626] key_create_or_update+0x174/0x510 [ 37.968863][T15626] __x64_sys_add_key+0x139/0x1d0 [ 37.969165][T15626] do_syscall_64+0x35/0xb0 [ 37.969451][T15626] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 37.969824][T15626] RIP: 0033:0x43a1f9 Signed-off-by: Xiaolong Huang <butterflyhuangxx@gmail.com> Tested-by: Xiaolong Huang <butterflyhuangxx@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2022-March/005069.html Fixes: 12da59fcab5a ("rxrpc: Hand server key parsing off to the security class") Link: https://lore.kernel.org/r/164865013439.2941502.8966285221215590921.stgit@warthog.procyon.org.uk Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net')
-rw-r--r--net/rxrpc/server_key.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/net/rxrpc/server_key.c b/net/rxrpc/server_key.c
index ead3471307ee..ee269e0e6ee8 100644
--- a/net/rxrpc/server_key.c
+++ b/net/rxrpc/server_key.c
@@ -84,6 +84,9 @@ static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
prep->payload.data[1] = (struct rxrpc_security *)sec;
+ if (!sec->preparse_server_key)
+ return -EINVAL;
+
return sec->preparse_server_key(prep);
}
@@ -91,7 +94,7 @@ static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
{
const struct rxrpc_security *sec = prep->payload.data[1];
- if (sec)
+ if (sec && sec->free_preparse_server_key)
sec->free_preparse_server_key(prep);
}
@@ -99,7 +102,7 @@ static void rxrpc_destroy_s(struct key *key)
{
const struct rxrpc_security *sec = key->payload.data[1];
- if (sec)
+ if (sec && sec->destroy_server_key)
sec->destroy_server_key(key);
}