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d41a3effbb
If a request_key authentication token key gets revoked, there's a window in
which request_key_auth_describe() can see it with a NULL payload - but it
makes no check for this and something like the following oops may occur:
BUG: Kernel NULL pointer dereference at 0x00000038
Faulting instruction address: 0xc0000000004ddf30
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP [...] request_key_auth_describe+0x90/0xd0
LR [...] request_key_auth_describe+0x54/0xd0
Call Trace:
[...] request_key_auth_describe+0x54/0xd0 (unreliable)
[...] proc_keys_show+0x308/0x4c0
[...] seq_read+0x3d0/0x540
[...] proc_reg_read+0x90/0x110
[...] __vfs_read+0x3c/0x70
[...] vfs_read+0xb4/0x1b0
[...] ksys_read+0x7c/0x130
[...] system_call+0x5c/0x70
Fix this by checking for a NULL pointer when describing such a key.
Also make the read routine check for a NULL pointer to be on the safe side.
[DH: Modified to not take already-held rcu lock and modified to also check
in the read routine]
Fixes:
|
||
|---|---|---|
| .. | ||
| encrypted-keys | ||
| big_key.c | ||
| compat_dh.c | ||
| compat.c | ||
| dh.c | ||
| gc.c | ||
| internal.h | ||
| Kconfig | ||
| key.c | ||
| keyctl_pkey.c | ||
| keyctl.c | ||
| keyring.c | ||
| Makefile | ||
| permission.c | ||
| persistent.c | ||
| proc.c | ||
| process_keys.c | ||
| request_key_auth.c | ||
| request_key.c | ||
| sysctl.c | ||
| trusted.c | ||
| user_defined.c | ||