From 1b986589680a2a5b6fc1ac196ea69925a93d9dd9 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Tue, 12 Mar 2019 10:23:02 -0700 Subject: bpf: Fix bpf_tcp_sock and bpf_sk_fullsock issue related to bpf_sk_release Lorenz Bauer [thanks!] reported that a ptr returned by bpf_tcp_sock(sk) can still be accessed after bpf_sk_release(sk). Both bpf_tcp_sock() and bpf_sk_fullsock() have the same issue. This patch addresses them together. A simple reproducer looks like this: sk = bpf_sk_lookup_tcp(); /* if (!sk) ... */ tp = bpf_tcp_sock(sk); /* if (!tp) ... */ bpf_sk_release(sk); snd_cwnd = tp->snd_cwnd; /* oops! The verifier does not complain. */ The problem is the verifier did not scrub the register's states of the tcp_sock ptr (tp) after bpf_sk_release(sk). [ Note that when calling bpf_tcp_sock(sk), the sk is not always refcount-acquired. e.g. bpf_tcp_sock(skb->sk). The verifier works fine for this case. ] Currently, the verifier does not track if a helper's return ptr (in REG_0) is "carry"-ing one of its argument's refcount status. To carry this info, the reg1->id needs to be stored in reg0. One approach was tried, like "reg0->id = reg1->id", when calling "bpf_tcp_sock()". The main idea was to avoid adding another "ref_obj_id" for the same reg. However, overlapping the NULL marking and ref tracking purpose in one "id" does not work well: ref_sk = bpf_sk_lookup_tcp(); fullsock = bpf_sk_fullsock(ref_sk); tp = bpf_tcp_sock(ref_sk); if (!fullsock) { bpf_sk_release(ref_sk); return 0; } /* fullsock_reg->id is marked for NOT-NULL. * Same for tp_reg->id because they have the same id. */ /* oops. verifier did not complain about the missing !tp check */ snd_cwnd = tp->snd_cwnd; Hence, a new "ref_obj_id" is needed in "struct bpf_reg_state". With a new ref_obj_id, when bpf_sk_release(sk) is called, the verifier can scrub all reg states which has a ref_obj_id match. It is done with the changes in release_reg_references() in this patch. While fixing it, sk_to_full_sk() is removed from bpf_tcp_sock() and bpf_sk_fullsock() to avoid these helpers from returning another ptr. It will make bpf_sk_release(tp) possible: sk = bpf_sk_lookup_tcp(); /* if (!sk) ... */ tp = bpf_tcp_sock(sk); /* if (!tp) ... */ bpf_sk_release(tp); A separate helper "bpf_get_listener_sock()" will be added in a later patch to do sk_to_full_sk(). Misc change notes: - To allow bpf_sk_release(tp), the arg of bpf_sk_release() is changed from ARG_PTR_TO_SOCKET to ARG_PTR_TO_SOCK_COMMON. ARG_PTR_TO_SOCKET is removed from bpf.h since no helper is using it. - arg_type_is_refcounted() is renamed to arg_type_may_be_refcounted() because ARG_PTR_TO_SOCK_COMMON is the only one and skb->sk is not refcounted. All bpf_sk_release(), bpf_sk_fullsock() and bpf_tcp_sock() take ARG_PTR_TO_SOCK_COMMON. - check_refcount_ok() ensures is_acquire_function() cannot take arg_type_may_be_refcounted() as its argument. - The check_func_arg() can only allow one refcount-ed arg. It is guaranteed by check_refcount_ok() which ensures at most one arg can be refcounted. Hence, it is a verifier internal error if >1 refcount arg found in check_func_arg(). - In release_reference(), release_reference_state() is called first to ensure a match on "reg->ref_obj_id" can be found before scrubbing the reg states with release_reg_references(). - reg_is_refcounted() is no longer needed. 1. In mark_ptr_or_null_regs(), its usage is replaced by "ref_obj_id && ref_obj_id == id" because, when is_null == true, release_reference_state() should only be called on the ref_obj_id obtained by a acquire helper (i.e. is_acquire_function() == true). Otherwise, the following would happen: sk = bpf_sk_lookup_tcp(); /* if (!sk) { ... } */ fullsock = bpf_sk_fullsock(sk); if (!fullsock) { /* * release_reference_state(fullsock_reg->ref_obj_id) * where fullsock_reg->ref_obj_id == sk_reg->ref_obj_id. * * Hence, the following bpf_sk_release(sk) will fail * because the ref state has already been released in the * earlier release_reference_state(fullsock_reg->ref_obj_id). */ bpf_sk_release(sk); } 2. In release_reg_references(), the current reg_is_refcounted() call is unnecessary because the id check is enough. - The type_is_refcounted() and type_is_refcounted_or_null() are no longer needed also because reg_is_refcounted() is removed. Fixes: 655a51e536c0 ("bpf: Add struct bpf_tcp_sock and BPF_FUNC_tcp_sock") Reported-by: Lorenz Bauer Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 1 - include/linux/bpf_verifier.h | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a2132e09dc1c..f02367faa58d 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -193,7 +193,6 @@ enum bpf_arg_type { ARG_PTR_TO_CTX, /* pointer to context */ ARG_ANYTHING, /* any (initialized) argument is ok */ - ARG_PTR_TO_SOCKET, /* pointer to bpf_sock */ ARG_PTR_TO_SPIN_LOCK, /* pointer to bpf_spin_lock */ ARG_PTR_TO_SOCK_COMMON, /* pointer to sock_common */ }; diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 69f7a3449eda..7d8228d1c898 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -66,6 +66,46 @@ struct bpf_reg_state { * same reference to the socket, to determine proper reference freeing. */ u32 id; + /* PTR_TO_SOCKET and PTR_TO_TCP_SOCK could be a ptr returned + * from a pointer-cast helper, bpf_sk_fullsock() and + * bpf_tcp_sock(). + * + * Consider the following where "sk" is a reference counted + * pointer returned from "sk = bpf_sk_lookup_tcp();": + * + * 1: sk = bpf_sk_lookup_tcp(); + * 2: if (!sk) { return 0; } + * 3: fullsock = bpf_sk_fullsock(sk); + * 4: if (!fullsock) { bpf_sk_release(sk); return 0; } + * 5: tp = bpf_tcp_sock(fullsock); + * 6: if (!tp) { bpf_sk_release(sk); return 0; } + * 7: bpf_sk_release(sk); + * 8: snd_cwnd = tp->snd_cwnd; // verifier will complain + * + * After bpf_sk_release(sk) at line 7, both "fullsock" ptr and + * "tp" ptr should be invalidated also. In order to do that, + * the reg holding "fullsock" and "sk" need to remember + * the original refcounted ptr id (i.e. sk_reg->id) in ref_obj_id + * such that the verifier can reset all regs which have + * ref_obj_id matching the sk_reg->id. + * + * sk_reg->ref_obj_id is set to sk_reg->id at line 1. + * sk_reg->id will stay as NULL-marking purpose only. + * After NULL-marking is done, sk_reg->id can be reset to 0. + * + * After "fullsock = bpf_sk_fullsock(sk);" at line 3, + * fullsock_reg->ref_obj_id is set to sk_reg->ref_obj_id. + * + * After "tp = bpf_tcp_sock(fullsock);" at line 5, + * tp_reg->ref_obj_id is set to fullsock_reg->ref_obj_id + * which is the same as sk_reg->ref_obj_id. + * + * From the verifier perspective, if sk, fullsock and tp + * are not NULL, they are the same ptr with different + * reg->type. In particular, bpf_sk_release(tp) is also + * allowed and has the same effect as bpf_sk_release(sk). + */ + u32 ref_obj_id; /* For scalar types (SCALAR_VALUE), this represents our knowledge of * the actual value. * For pointer types, this represents the variable part of the offset -- cgit v1.2.3 From 9804501fa1228048857910a6bf23e085aade37cc Mon Sep 17 00:00:00 2001 From: YueHaibing Date: Thu, 14 Mar 2019 13:47:59 +0800 Subject: appletalk: Fix potential NULL pointer dereference in unregister_snap_client register_snap_client may return NULL, all the callers check it, but only print a warning. This will result in NULL pointer dereference in unregister_snap_client and other places. It has always been used like this since v2.6 Reported-by: Dan Carpenter Signed-off-by: YueHaibing Signed-off-by: David S. Miller --- include/linux/atalk.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/atalk.h b/include/linux/atalk.h index d5cfc0b15b76..f6034ba774be 100644 --- a/include/linux/atalk.h +++ b/include/linux/atalk.h @@ -108,7 +108,7 @@ static __inline__ struct elapaarp *aarp_hdr(struct sk_buff *skb) #define AARP_RESOLVE_TIME (10 * HZ) extern struct datalink_proto *ddp_dl, *aarp_dl; -extern void aarp_proto_init(void); +extern int aarp_proto_init(void); /* Inter module exports */ -- cgit v1.2.3 From 8a3c245c031944f2176118270e7bc5d4fd4a1075 Mon Sep 17 00:00:00 2001 From: Pedro Tammela Date: Thu, 14 Mar 2019 10:45:23 -0300 Subject: net: add documentation to socket.c Adds missing sphinx documentation to the socket.c's functions. Also fixes some whitespaces. I also changed the style of older documentation as an effort to have an uniform documentation style. Signed-off-by: Pedro Tammela Signed-off-by: David S. Miller --- include/linux/net.h | 6 ++++++ include/linux/socket.h | 12 ++++++------ 2 files changed, 12 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/net.h b/include/linux/net.h index 651fca72286c..c606c72311d0 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -83,6 +83,12 @@ enum sock_type { #endif /* ARCH_HAS_SOCKET_TYPES */ +/** + * enum sock_shutdown_cmd - Shutdown types + * @SHUT_RD: shutdown receptions + * @SHUT_WR: shutdown transmissions + * @SHUT_RDWR: shutdown receptions/transmissions + */ enum sock_shutdown_cmd { SHUT_RD, SHUT_WR, diff --git a/include/linux/socket.h b/include/linux/socket.h index 6016daeecee4..b57cd8bf96e2 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -26,7 +26,7 @@ typedef __kernel_sa_family_t sa_family_t; /* * 1003.1g requires sa_family_t and that sa_data is char. */ - + struct sockaddr { sa_family_t sa_family; /* address family, AF_xxx */ char sa_data[14]; /* 14 bytes of protocol address */ @@ -44,7 +44,7 @@ struct linger { * system, not 4.3. Thus msg_accrights(len) are now missing. They * belong in an obscure libc emulation or the bin. */ - + struct msghdr { void *msg_name; /* ptr to socket address structure */ int msg_namelen; /* size of socket address structure */ @@ -54,7 +54,7 @@ struct msghdr { unsigned int msg_flags; /* flags on received message */ struct kiocb *msg_iocb; /* ptr to iocb for async requests */ }; - + struct user_msghdr { void __user *msg_name; /* ptr to socket address structure */ int msg_namelen; /* size of socket address structure */ @@ -122,7 +122,7 @@ struct cmsghdr { * inside range, given by msg->msg_controllen before using * ancillary object DATA. --ANK (980731) */ - + static inline struct cmsghdr * __cmsg_nxthdr(void *__ctl, __kernel_size_t __size, struct cmsghdr *__cmsg) { @@ -264,10 +264,10 @@ struct ucred { /* Maximum queue length specifiable by listen. */ #define SOMAXCONN 128 -/* Flags we can use with send/ and recv. +/* Flags we can use with send/ and recv. Added those for 1003.1g not all are supported yet */ - + #define MSG_OOB 1 #define MSG_PEEK 2 #define MSG_DONTROUTE 4 -- cgit v1.2.3 From 450895d04ba13a96886eddfeddb11556ae8624f1 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sun, 24 Mar 2019 00:18:46 +0200 Subject: net: phy: bcm54xx: Encode link speed and activity into LEDs Previously the green and amber LEDs on this quad PHY were solid, to indicate an encoding of the link speed (10/100/1000). This keeps the LEDs always on just as before, but now they flash on Rx/Tx activity. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- include/linux/brcmphy.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/linux') diff --git a/include/linux/brcmphy.h b/include/linux/brcmphy.h index 9cd00a37b8d3..6db2d9a6e503 100644 --- a/include/linux/brcmphy.h +++ b/include/linux/brcmphy.h @@ -148,6 +148,22 @@ #define BCM_LED_SRC_OFF 0xe /* Tied high */ #define BCM_LED_SRC_ON 0xf /* Tied low */ +/* + * Broadcom Multicolor LED configurations (expansion register 4) + */ +#define BCM_EXP_MULTICOLOR (MII_BCM54XX_EXP_SEL_ER + 0x04) +#define BCM_LED_MULTICOLOR_IN_PHASE BIT(8) +#define BCM_LED_MULTICOLOR_LINK_ACT 0x0 +#define BCM_LED_MULTICOLOR_SPEED 0x1 +#define BCM_LED_MULTICOLOR_ACT_FLASH 0x2 +#define BCM_LED_MULTICOLOR_FDX 0x3 +#define BCM_LED_MULTICOLOR_OFF 0x4 +#define BCM_LED_MULTICOLOR_ON 0x5 +#define BCM_LED_MULTICOLOR_ALT 0x6 +#define BCM_LED_MULTICOLOR_FLASH 0x7 +#define BCM_LED_MULTICOLOR_LINK 0x8 +#define BCM_LED_MULTICOLOR_ACT 0x9 +#define BCM_LED_MULTICOLOR_PROGRAM 0xa /* * BCM5482: Shadow registers -- cgit v1.2.3