| Message ID | 20220322162822.566705-1-butterflyhuangxx@gmail.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | rxrpc: fix some null-ptr-deref bugs in server_key.c | expand |
Xiaolong Huang <butterflyhuangxx@gmail.com> wrote:
> user@syzkaller:~$ ./rxrpc_preparse_s
Is there a syzbot report to reference for this?
David
No other syzbot report references it. Regards, butt3rflyh4ck. On Mon, Mar 28, 2022 at 7:57 PM David Howells <dhowells@redhat.com> wrote: > > Xiaolong Huang <butterflyhuangxx@gmail.com> wrote: > > > user@syzkaller:~$ ./rxrpc_preparse_s > > Is there a syzbot report to reference for this? > > David >
On Tue, Mar 22, 2022 at 1:28 PM Xiaolong Huang <butterflyhuangxx@gmail.com> wrote: > > 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> > --- > net/rxrpc/server_key.c | 7 +++++-- > 1 file 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); > } > > > base-commit: b47d5a4f6b8d42f8a8fbe891b36215e4fddc53be > -- > 2.25.1 Actually ran into this while experimenting; looks fine and fixes the problem. Acked-by: Marc Dionne <marc.dionne@auristor.com> Marc
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); }