From b178c94efdfd7e7c649277c0f570c5db14aaba4f Mon Sep 17 00:00:00 2001 From: Jan Luebbe Date: Mon, 28 Aug 2017 17:25:16 +0200 Subject: bus: mbus: fix window size calculation for 4GB windows commit 2bbbd96357ce76cc45ec722c00f654aa7b189112 upstream. At least the Armada XP SoC supports 4GB on a single DRAM window. Because the size register values contain the actual size - 1, the MSB is set in that case. For example, the SDRAM window's control register's value is 0xffffffe1 for 4GB (bits 31 to 24 contain the size). The MBUS driver reads back each window's size from registers and calculates the actual size as (control_reg | ~DDR_SIZE_MASK) + 1, which overflows for 32 bit values, resulting in other miscalculations further on (a bad RAM window for the CESA crypto engine calculated by mvebu_mbus_setup_cpu_target_nooverlap() in my case). This patch changes the type in 'struct mbus_dram_window' from u32 to u64, which allows us to keep using the same register calculation code in most MBUS-using drivers (which calculate ->size - 1 again). Fixes: fddddb52a6c4 ("bus: introduce an Marvell EBU MBus driver") Signed-off-by: Jan Luebbe Signed-off-by: Gregory CLEMENT Signed-off-by: Greg Kroah-Hartman --- include/linux/mbus.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mbus.h b/include/linux/mbus.h index 1f7bc630d225..71a5a56b0bba 100644 --- a/include/linux/mbus.h +++ b/include/linux/mbus.h @@ -29,8 +29,8 @@ struct mbus_dram_target_info struct mbus_dram_window { u8 cs_index; u8 mbus_attr; - u32 base; - u32 size; + u64 base; + u64 size; } cs[4]; }; -- cgit v1.2.3 From 8a004caec12bf241e567e3640401256cc9bc2e45 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 4 Oct 2017 16:43:25 +0100 Subject: KEYS: Fix race between updating and finding a negative key commit 363b02dab09b3226f3bd1420dad9c72b79a42a76 upstream. Consolidate KEY_FLAG_INSTANTIATED, KEY_FLAG_NEGATIVE and the rejection error into one field such that: (1) The instantiation state can be modified/read atomically. (2) The error can be accessed atomically with the state. (3) The error isn't stored unioned with the payload pointers. This deals with the problem that the state is spread over three different objects (two bits and a separate variable) and reading or updating them atomically isn't practical, given that not only can uninstantiated keys change into instantiated or rejected keys, but rejected keys can also turn into instantiated keys - and someone accessing the key might not be using any locking. The main side effect of this problem is that what was held in the payload may change, depending on the state. For instance, you might observe the key to be in the rejected state. You then read the cached error, but if the key semaphore wasn't locked, the key might've become instantiated between the two reads - and you might now have something in hand that isn't actually an error code. The state is now KEY_IS_UNINSTANTIATED, KEY_IS_POSITIVE or a negative error code if the key is negatively instantiated. The key_is_instantiated() function is replaced with key_is_positive() to avoid confusion as negative keys are also 'instantiated'. Additionally, barriering is included: (1) Order payload-set before state-set during instantiation. (2) Order state-read before payload-read when using the key. Further separate barriering is necessary if RCU is being used to access the payload content after reading the payload pointers. Fixes: 146aa8b1453b ("KEYS: Merge the type-specific data with the payload data") Reported-by: Eric Biggers Signed-off-by: David Howells Reviewed-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman --- include/linux/key.h | 49 +++++++++++++++++++++++++++++++------------------ 1 file changed, 31 insertions(+), 18 deletions(-) (limited to 'include/linux') diff --git a/include/linux/key.h b/include/linux/key.h index dcc115e8dd03..af071ca73079 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -126,6 +126,11 @@ static inline bool is_key_possessed(const key_ref_t key_ref) return (unsigned long) key_ref & 1UL; } +enum key_state { + KEY_IS_UNINSTANTIATED, + KEY_IS_POSITIVE, /* Positively instantiated */ +}; + /*****************************************************************************/ /* * authentication token / access credential / keyring @@ -157,6 +162,7 @@ struct key { * - may not match RCU dereferenced payload * - payload should contain own length */ + short state; /* Key state (+) or rejection error (-) */ #ifdef KEY_DEBUGGING unsigned magic; @@ -165,19 +171,17 @@ struct key { #endif unsigned long flags; /* status flags (change with bitops) */ -#define KEY_FLAG_INSTANTIATED 0 /* set if key has been instantiated */ -#define KEY_FLAG_DEAD 1 /* set if key type has been deleted */ -#define KEY_FLAG_REVOKED 2 /* set if key had been revoked */ -#define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */ -#define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */ -#define KEY_FLAG_NEGATIVE 5 /* set if key is negative */ -#define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */ -#define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */ -#define KEY_FLAG_TRUSTED 8 /* set if key is trusted */ -#define KEY_FLAG_TRUSTED_ONLY 9 /* set if keyring only accepts links to trusted keys */ -#define KEY_FLAG_BUILTIN 10 /* set if key is builtin */ -#define KEY_FLAG_ROOT_CAN_INVAL 11 /* set if key can be invalidated by root without permission */ -#define KEY_FLAG_UID_KEYRING 12 /* set if key is a user or user session keyring */ +#define KEY_FLAG_DEAD 0 /* set if key type has been deleted */ +#define KEY_FLAG_REVOKED 1 /* set if key had been revoked */ +#define KEY_FLAG_IN_QUOTA 2 /* set if key consumes quota */ +#define KEY_FLAG_USER_CONSTRUCT 3 /* set if key is being constructed in userspace */ +#define KEY_FLAG_ROOT_CAN_CLEAR 4 /* set if key can be cleared by root without permission */ +#define KEY_FLAG_INVALIDATED 5 /* set if key has been invalidated */ +#define KEY_FLAG_TRUSTED 6 /* set if key is trusted */ +#define KEY_FLAG_TRUSTED_ONLY 7 /* set if keyring only accepts links to trusted keys */ +#define KEY_FLAG_BUILTIN 8 /* set if key is builtin */ +#define KEY_FLAG_ROOT_CAN_INVAL 9 /* set if key can be invalidated by root without permission */ +#define KEY_FLAG_UID_KEYRING 10 /* set if key is a user or user session keyring */ /* the key type and key description string * - the desc is used to match a key against search criteria @@ -203,7 +207,6 @@ struct key { struct list_head name_link; struct assoc_array keys; }; - int reject_error; }; }; @@ -319,17 +322,27 @@ extern void key_set_timeout(struct key *, unsigned); #define KEY_NEED_SETATTR 0x20 /* Require permission to change attributes */ #define KEY_NEED_ALL 0x3f /* All the above permissions */ +static inline short key_read_state(const struct key *key) +{ + /* Barrier versus mark_key_instantiated(). */ + return smp_load_acquire(&key->state); +} + /** - * key_is_instantiated - Determine if a key has been positively instantiated + * key_is_positive - Determine if a key has been positively instantiated * @key: The key to check. * * Return true if the specified key has been positively instantiated, false * otherwise. */ -static inline bool key_is_instantiated(const struct key *key) +static inline bool key_is_positive(const struct key *key) +{ + return key_read_state(key) == KEY_IS_POSITIVE; +} + +static inline bool key_is_negative(const struct key *key) { - return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) && - !test_bit(KEY_FLAG_NEGATIVE, &key->flags); + return key_read_state(key) < 0; } #define rcu_dereference_key(KEY) \ -- cgit v1.2.3