| Message ID | 164865013439.2941502.8966285221215590921.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | ff8376ade4f668130385839cef586a0990f8ef87 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] rxrpc: fix some null-ptr-deref bugs in server_key.c | expand |
On Wed, 2022-03-30 at 15:22 +0100, David Howells wrote: > From: Xiaolong Huang <butterflyhuangxx@gmail.com> > > 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 It looks like we can add a couple of fixes tag to help stable teams: Fixes: d5953f6543b5 ("rxrpc: Allow security classes to give more info on server keys") Fixes: 12da59fcab5a ("xrpc: Hand server key parsing off to the security class") Does the above looks good to you? Thanks! Paolo
Paolo Abeni <pabeni@redhat.com> wrote: > It looks like we can add a couple of fixes tag to help stable teams: > > Fixes: d5953f6543b5 ("rxrpc: Allow security classes to give more info on server keys") Not this one. This includes a check for the one op it adds: + if (sec && sec->describe_server_key) + sec->describe_server_key(key, m); > Fixes: 12da59fcab5a ("xrpc: Hand server key parsing off to the security class") There's a missing 'r' in "rxrpc:" in the patch subject, but otherwise this one looks like the right one. Thanks, David
On Thu, 2022-03-31 at 13:16 +0100, David Howells wrote: > Paolo Abeni <pabeni@redhat.com> wrote: > > > It looks like we can add a couple of fixes tag to help stable teams: > > > > Fixes: d5953f6543b5 ("rxrpc: Allow security classes to give more info on server keys") > > Not this one. This includes a check for the one op it adds: > > + if (sec && sec->describe_server_key) > + sec->describe_server_key(key, m); > > > > Fixes: 12da59fcab5a ("xrpc: Hand server key parsing off to the security class") > > There's a missing 'r' in "rxrpc:" in the patch subject, but otherwise this one > looks like the right one. Thank you for double-checking. No need to repost, I'll add the tag while applying it. Cheeers, Paolo
Hello: This patch was applied to netdev/net.git (master) by Paolo Abeni <pabeni@redhat.com>: On Wed, 30 Mar 2022 15:22:14 +0100 you wrote: > From: Xiaolong Huang <butterflyhuangxx@gmail.com> > > 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 > > [...] Here is the summary with links: - [net] rxrpc: fix some null-ptr-deref bugs in server_key.c https://git.kernel.org/netdev/net/c/ff8376ade4f6 You are awesome, thank you!
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); }