From ef5828805842204dd0259ecfc132b5916c8a77ae Mon Sep 17 00:00:00 2001 From: Michael-CY Lee Date: Wed, 22 Nov 2023 11:02:37 +0800 Subject: wifi: avoid offset calculation on NULL pointer ieee80211_he_6ghz_oper() can be passed a NULL pointer and checks for that, but already did the calculation to inside of it before. Move it after the check. Signed-off-by: Michael-CY Lee Link: https://lore.kernel.org/r/20231122030237.31276-1-michael-cy.lee@mediatek.com [rewrite commit message] Signed-off-by: Johannes Berg --- include/linux/ieee80211.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index 958771bac9c0..c2ac9e9e7ee9 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -2830,12 +2830,14 @@ ieee80211_he_oper_size(const u8 *he_oper_ie) static inline const struct ieee80211_he_6ghz_oper * ieee80211_he_6ghz_oper(const struct ieee80211_he_operation *he_oper) { - const u8 *ret = (const void *)&he_oper->optional; + const u8 *ret; u32 he_oper_params; if (!he_oper) return NULL; + ret = (const void *)&he_oper->optional; + he_oper_params = le32_to_cpu(he_oper->he_oper_params); if (!(he_oper_params & IEEE80211_HE_OPERATION_6GHZ_OP_INFO)) -- cgit v1.2.3 From 8c88a474357ead632b07c70bf7f119ace8c3b39e Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 24 Nov 2023 17:25:26 +0100 Subject: debugfs: add API to allow debugfs operations cancellation In some cases there might be longer-running hardware accesses in debugfs files, or attempts to acquire locks, and we want to still be able to quickly remove the files. Introduce a cancellations API to use inside the debugfs handler functions to be able to cancel such operations on a per-file basis. Acked-by: Greg Kroah-Hartman Signed-off-by: Johannes Berg --- fs/debugfs/file.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++ fs/debugfs/inode.c | 32 ++++++++++++++++++- fs/debugfs/internal.h | 5 +++ include/linux/debugfs.h | 19 ++++++++++++ 4 files changed, 137 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 3eff92450fd5..5568cdea3490 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -114,6 +114,8 @@ int debugfs_file_get(struct dentry *dentry) lockdep_init_map(&fsd->lockdep_map, fsd->lock_name ?: "debugfs", &fsd->key, 0); #endif + INIT_LIST_HEAD(&fsd->cancellations); + mutex_init(&fsd->cancellations_mtx); } /* @@ -156,6 +158,86 @@ void debugfs_file_put(struct dentry *dentry) } EXPORT_SYMBOL_GPL(debugfs_file_put); +/** + * debugfs_enter_cancellation - enter a debugfs cancellation + * @file: the file being accessed + * @cancellation: the cancellation object, the cancel callback + * inside of it must be initialized + * + * When a debugfs file is removed it needs to wait for all active + * operations to complete. However, the operation itself may need + * to wait for hardware or completion of some asynchronous process + * or similar. As such, it may need to be cancelled to avoid long + * waits or even deadlocks. + * + * This function can be used inside a debugfs handler that may + * need to be cancelled. As soon as this function is called, the + * cancellation's 'cancel' callback may be called, at which point + * the caller should proceed to call debugfs_leave_cancellation() + * and leave the debugfs handler function as soon as possible. + * Note that the 'cancel' callback is only ever called in the + * context of some kind of debugfs_remove(). + * + * This function must be paired with debugfs_leave_cancellation(). + */ +void debugfs_enter_cancellation(struct file *file, + struct debugfs_cancellation *cancellation) +{ + struct debugfs_fsdata *fsd; + struct dentry *dentry = F_DENTRY(file); + + INIT_LIST_HEAD(&cancellation->list); + + if (WARN_ON(!d_is_reg(dentry))) + return; + + if (WARN_ON(!cancellation->cancel)) + return; + + fsd = READ_ONCE(dentry->d_fsdata); + if (WARN_ON(!fsd || + ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT))) + return; + + mutex_lock(&fsd->cancellations_mtx); + list_add(&cancellation->list, &fsd->cancellations); + mutex_unlock(&fsd->cancellations_mtx); + + /* if we're already removing wake it up to cancel */ + if (d_unlinked(dentry)) + complete(&fsd->active_users_drained); +} +EXPORT_SYMBOL_GPL(debugfs_enter_cancellation); + +/** + * debugfs_leave_cancellation - leave cancellation section + * @file: the file being accessed + * @cancellation: the cancellation previously registered with + * debugfs_enter_cancellation() + * + * See the documentation of debugfs_enter_cancellation(). + */ +void debugfs_leave_cancellation(struct file *file, + struct debugfs_cancellation *cancellation) +{ + struct debugfs_fsdata *fsd; + struct dentry *dentry = F_DENTRY(file); + + if (WARN_ON(!d_is_reg(dentry))) + return; + + fsd = READ_ONCE(dentry->d_fsdata); + if (WARN_ON(!fsd || + ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT))) + return; + + mutex_lock(&fsd->cancellations_mtx); + if (!list_empty(&cancellation->list)) + list_del(&cancellation->list); + mutex_unlock(&fsd->cancellations_mtx); +} +EXPORT_SYMBOL_GPL(debugfs_leave_cancellation); + /* * Only permit access to world-readable files when the kernel is locked down. * We also need to exclude any file that has ways to write or alter it as root diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 80f4f000dcc1..d53c2860b03c 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -247,6 +247,8 @@ static void debugfs_release_dentry(struct dentry *dentry) lockdep_unregister_key(&fsd->key); kfree(fsd->lock_name); #endif + WARN_ON(!list_empty(&fsd->cancellations)); + mutex_destroy(&fsd->cancellations_mtx); } kfree(fsd); @@ -756,8 +758,36 @@ static void __debugfs_file_removed(struct dentry *dentry) lock_map_acquire(&fsd->lockdep_map); lock_map_release(&fsd->lockdep_map); - if (!refcount_dec_and_test(&fsd->active_users)) + /* if we hit zero, just wait for all to finish */ + if (!refcount_dec_and_test(&fsd->active_users)) { wait_for_completion(&fsd->active_users_drained); + return; + } + + /* if we didn't hit zero, try to cancel any we can */ + while (refcount_read(&fsd->active_users)) { + struct debugfs_cancellation *c; + + /* + * Lock the cancellations. Note that the cancellations + * structs are meant to be on the stack, so we need to + * ensure we either use them here or don't touch them, + * and debugfs_leave_cancellation() will wait for this + * to be finished processing before exiting one. It may + * of course win and remove the cancellation, but then + * chances are we never even got into this bit, we only + * do if the refcount isn't zero already. + */ + mutex_lock(&fsd->cancellations_mtx); + while ((c = list_first_entry_or_null(&fsd->cancellations, + typeof(*c), list))) { + list_del_init(&c->list); + c->cancel(dentry, c->cancel_data); + } + mutex_unlock(&fsd->cancellations_mtx); + + wait_for_completion(&fsd->active_users_drained); + } } static void remove_one(struct dentry *victim) diff --git a/fs/debugfs/internal.h b/fs/debugfs/internal.h index c7d61cfc97d2..0c4c68cf161f 100644 --- a/fs/debugfs/internal.h +++ b/fs/debugfs/internal.h @@ -8,6 +8,7 @@ #ifndef _DEBUGFS_INTERNAL_H_ #define _DEBUGFS_INTERNAL_H_ #include +#include struct file_operations; @@ -29,6 +30,10 @@ struct debugfs_fsdata { struct lock_class_key key; char *lock_name; #endif + + /* protect cancellations */ + struct mutex cancellations_mtx; + struct list_head cancellations; }; }; }; diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index ea2d919fd9c7..c9c65b132c0f 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -171,6 +171,25 @@ ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, size_t count, loff_t *ppos); +/** + * struct debugfs_cancellation - cancellation data + * @list: internal, for keeping track + * @cancel: callback to call + * @cancel_data: extra data for the callback to call + */ +struct debugfs_cancellation { + struct list_head list; + void (*cancel)(struct dentry *, void *); + void *cancel_data; +}; + +void __acquires(cancellation) +debugfs_enter_cancellation(struct file *file, + struct debugfs_cancellation *cancellation); +void __releases(cancellation) +debugfs_leave_cancellation(struct file *file, + struct debugfs_cancellation *cancellation); + #else #include -- cgit v1.2.3 From b590b9ae1efc30e52f81d95cdb2519a4c248b965 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 24 Nov 2023 17:25:27 +0100 Subject: wifi: cfg80211: add locked debugfs wrappers Add wrappers for debugfs files that should be called with the wiphy mutex held, while the file is also to be removed under the wiphy mutex. This could otherwise deadlock when a file is trying to acquire the wiphy mutex while the code removing it holds the mutex but waits for the removal. This actually works by pushing the execution of the read or write handler to a wiphy work that can be cancelled using the debugfs cancellation API. Signed-off-by: Johannes Berg --- include/net/cfg80211.h | 46 ++++++++++++++ net/wireless/debugfs.c | 160 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 206 insertions(+) (limited to 'include') diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index b137a33a1b68..4ecfb06c413d 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -9299,4 +9299,50 @@ bool cfg80211_valid_disable_subchannel_bitmap(u16 *bitmap, */ void cfg80211_links_removed(struct net_device *dev, u16 link_mask); +#ifdef CONFIG_CFG80211_DEBUGFS +/** + * wiphy_locked_debugfs_read - do a locked read in debugfs + * @wiphy: the wiphy to use + * @file: the file being read + * @buf: the buffer to fill and then read from + * @bufsize: size of the buffer + * @userbuf: the user buffer to copy to + * @count: read count + * @ppos: read position + * @handler: the read handler to call (under wiphy lock) + * @data: additional data to pass to the read handler + */ +ssize_t wiphy_locked_debugfs_read(struct wiphy *wiphy, struct file *file, + char *buf, size_t bufsize, + char __user *userbuf, size_t count, + loff_t *ppos, + ssize_t (*handler)(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t bufsize, + void *data), + void *data); + +/** + * wiphy_locked_debugfs_write - do a locked write in debugfs + * @wiphy: the wiphy to use + * @file: the file being written to + * @buf: the buffer to copy the user data to + * @bufsize: size of the buffer + * @userbuf: the user buffer to copy from + * @count: read count + * @handler: the write handler to call (under wiphy lock) + * @data: additional data to pass to the write handler + */ +ssize_t wiphy_locked_debugfs_write(struct wiphy *wiphy, struct file *file, + char *buf, size_t bufsize, + const char __user *userbuf, size_t count, + ssize_t (*handler)(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t count, + void *data), + void *data); +#endif + #endif /* __NET_CFG80211_H */ diff --git a/net/wireless/debugfs.c b/net/wireless/debugfs.c index 0878b162890a..40e49074e2ee 100644 --- a/net/wireless/debugfs.c +++ b/net/wireless/debugfs.c @@ -4,6 +4,7 @@ * * Copyright 2009 Luis R. Rodriguez * Copyright 2007 Johannes Berg + * Copyright (C) 2023 Intel Corporation */ #include @@ -109,3 +110,162 @@ void cfg80211_debugfs_rdev_add(struct cfg80211_registered_device *rdev) DEBUGFS_ADD(long_retry_limit); DEBUGFS_ADD(ht40allow_map); } + +struct debugfs_read_work { + struct wiphy_work work; + ssize_t (*handler)(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t count, + void *data); + struct wiphy *wiphy; + struct file *file; + char *buf; + size_t bufsize; + void *data; + ssize_t ret; + struct completion completion; +}; + +static void wiphy_locked_debugfs_read_work(struct wiphy *wiphy, + struct wiphy_work *work) +{ + struct debugfs_read_work *w = container_of(work, typeof(*w), work); + + w->ret = w->handler(w->wiphy, w->file, w->buf, w->bufsize, w->data); + complete(&w->completion); +} + +static void wiphy_locked_debugfs_read_cancel(struct dentry *dentry, + void *data) +{ + struct debugfs_read_work *w = data; + + wiphy_work_cancel(w->wiphy, &w->work); + complete(&w->completion); +} + +ssize_t wiphy_locked_debugfs_read(struct wiphy *wiphy, struct file *file, + char *buf, size_t bufsize, + char __user *userbuf, size_t count, + loff_t *ppos, + ssize_t (*handler)(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t bufsize, + void *data), + void *data) +{ + struct debugfs_read_work work = { + .handler = handler, + .wiphy = wiphy, + .file = file, + .buf = buf, + .bufsize = bufsize, + .data = data, + .ret = -ENODEV, + .completion = COMPLETION_INITIALIZER_ONSTACK(work.completion), + }; + struct debugfs_cancellation cancellation = { + .cancel = wiphy_locked_debugfs_read_cancel, + .cancel_data = &work, + }; + + /* don't leak stack data or whatever */ + memset(buf, 0, bufsize); + + wiphy_work_init(&work.work, wiphy_locked_debugfs_read_work); + wiphy_work_queue(wiphy, &work.work); + + debugfs_enter_cancellation(file, &cancellation); + wait_for_completion(&work.completion); + debugfs_leave_cancellation(file, &cancellation); + + if (work.ret < 0) + return work.ret; + + if (WARN_ON(work.ret > bufsize)) + return -EINVAL; + + return simple_read_from_buffer(userbuf, count, ppos, buf, work.ret); +} +EXPORT_SYMBOL_GPL(wiphy_locked_debugfs_read); + +struct debugfs_write_work { + struct wiphy_work work; + ssize_t (*handler)(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t count, + void *data); + struct wiphy *wiphy; + struct file *file; + char *buf; + size_t count; + void *data; + ssize_t ret; + struct completion completion; +}; + +static void wiphy_locked_debugfs_write_work(struct wiphy *wiphy, + struct wiphy_work *work) +{ + struct debugfs_write_work *w = container_of(work, typeof(*w), work); + + w->ret = w->handler(w->wiphy, w->file, w->buf, w->count, w->data); + complete(&w->completion); +} + +static void wiphy_locked_debugfs_write_cancel(struct dentry *dentry, + void *data) +{ + struct debugfs_write_work *w = data; + + wiphy_work_cancel(w->wiphy, &w->work); + complete(&w->completion); +} + +ssize_t wiphy_locked_debugfs_write(struct wiphy *wiphy, + struct file *file, char *buf, size_t bufsize, + const char __user *userbuf, size_t count, + ssize_t (*handler)(struct wiphy *wiphy, + struct file *file, + char *buf, + size_t count, + void *data), + void *data) +{ + struct debugfs_write_work work = { + .handler = handler, + .wiphy = wiphy, + .file = file, + .buf = buf, + .count = count, + .data = data, + .ret = -ENODEV, + .completion = COMPLETION_INITIALIZER_ONSTACK(work.completion), + }; + struct debugfs_cancellation cancellation = { + .cancel = wiphy_locked_debugfs_write_cancel, + .cancel_data = &work, + }; + + /* mostly used for strings so enforce NUL-termination for safety */ + if (count >= bufsize) + return -EINVAL; + + memset(buf, 0, bufsize); + + if (copy_from_user(buf, userbuf, count)) + return -EFAULT; + + wiphy_work_init(&work.work, wiphy_locked_debugfs_write_work); + wiphy_work_queue(wiphy, &work.work); + + debugfs_enter_cancellation(file, &cancellation); + wait_for_completion(&work.completion); + debugfs_leave_cancellation(file, &cancellation); + + return work.ret; +} +EXPORT_SYMBOL_GPL(wiphy_locked_debugfs_write); -- cgit v1.2.3 From 45b3fae4675dc1d4ee2d7aefa19d85ee4f891377 Mon Sep 17 00:00:00 2001 From: Gustavo A. R. Silva Date: Sat, 25 Nov 2023 15:33:58 -0600 Subject: neighbour: Fix __randomize_layout crash in struct neighbour Previously, one-element and zero-length arrays were treated as true flexible arrays, even though they are actually "fake" flex arrays. The __randomize_layout would leave them untouched at the end of the struct, similarly to proper C99 flex-array members. However, this approach changed with commit 1ee60356c2dc ("gcc-plugins: randstruct: Only warn about true flexible arrays"). Now, only C99 flexible-array members will remain untouched at the end of the struct, while one-element and zero-length arrays will be subject to randomization. Fix a `__randomize_layout` crash in `struct neighbour` by transforming zero-length array `primary_key` into a proper C99 flexible-array member. Fixes: 1ee60356c2dc ("gcc-plugins: randstruct: Only warn about true flexible arrays") Closes: https://lore.kernel.org/linux-hardening/20231124102458.GB1503258@e124191.cambridge.arm.com/ Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook Tested-by: Joey Gouly Link: https://lore.kernel.org/r/ZWJoRsJGnCPdJ3+2@work Signed-off-by: Paolo Abeni --- include/net/neighbour.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 07022bb0d44d..0d28172193fa 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -162,7 +162,7 @@ struct neighbour { struct rcu_head rcu; struct net_device *dev; netdevice_tracker dev_tracker; - u8 primary_key[0]; + u8 primary_key[]; } __randomize_layout; struct neigh_ops { -- cgit v1.2.3 From 8866730aed5100f06d3d965c22f1c61f74942541 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Tue, 28 Nov 2023 17:25:56 -0800 Subject: bpf, sockmap: af_unix stream sockets need to hold ref for pair sock AF_UNIX stream sockets are a paired socket. So sending on one of the pairs will lookup the paired socket as part of the send operation. It is possible however to put just one of the pairs in a BPF map. This currently increments the refcnt on the sock in the sockmap to ensure it is not free'd by the stack before sockmap cleans up its state and stops any skbs being sent/recv'd to that socket. But we missed a case. If the peer socket is closed it will be free'd by the stack. However, the paired socket can still be referenced from BPF sockmap side because we hold a reference there. Then if we are sending traffic through BPF sockmap to that socket it will try to dereference the free'd pair in its send logic creating a use after free. And following splat: [59.900375] BUG: KASAN: slab-use-after-free in sk_wake_async+0x31/0x1b0 [59.901211] Read of size 8 at addr ffff88811acbf060 by task kworker/1:2/954 [...] [59.905468] Call Trace: [59.905787] [59.906066] dump_stack_lvl+0x130/0x1d0 [59.908877] print_report+0x16f/0x740 [59.910629] kasan_report+0x118/0x160 [59.912576] sk_wake_async+0x31/0x1b0 [59.913554] sock_def_readable+0x156/0x2a0 [59.914060] unix_stream_sendmsg+0x3f9/0x12a0 [59.916398] sock_sendmsg+0x20e/0x250 [59.916854] skb_send_sock+0x236/0xac0 [59.920527] sk_psock_backlog+0x287/0xaa0 To fix let BPF sockmap hold a refcnt on both the socket in the sockmap and its paired socket. It wasn't obvious how to contain the fix to bpf_unix logic. The primarily problem with keeping this logic in bpf_unix was: In the sock close() we could handle the deref by having a close handler. But, when we are destroying the psock through a map delete operation we wouldn't have gotten any signal thorugh the proto struct other than it being replaced. If we do the deref from the proto replace its too early because we need to deref the sk_pair after the backlog worker has been stopped. Given all this it seems best to just cache it at the end of the psock and eat 8B for the af_unix and vsock users. Notice dgram sockets are OK because they handle locking already. Fixes: 94531cfcbe79 ("af_unix: Add unix_stream_proto for sockmap") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Reviewed-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20231129012557.95371-2-john.fastabend@gmail.com --- include/linux/skmsg.h | 1 + include/net/af_unix.h | 1 + net/core/skmsg.c | 2 ++ net/unix/af_unix.c | 2 -- net/unix/unix_bpf.c | 5 +++++ 5 files changed, 9 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index c1637515a8a4..c953b8c0d2f4 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -106,6 +106,7 @@ struct sk_psock { struct mutex work_mutex; struct sk_psock_work_state work_state; struct delayed_work work; + struct sock *sk_pair; struct rcu_work rwork; }; diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 824c258143a3..49c4640027d8 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -75,6 +75,7 @@ struct unix_sock { }; #define unix_sk(ptr) container_of_const(ptr, struct unix_sock, sk) +#define unix_peer(sk) (unix_sk(sk)->peer) #define peer_wait peer_wq.wait diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 6c31eefbd777..93ecfceac1bc 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -826,6 +826,8 @@ static void sk_psock_destroy(struct work_struct *work) if (psock->sk_redir) sock_put(psock->sk_redir); + if (psock->sk_pair) + sock_put(psock->sk_pair); sock_put(psock->sk); kfree(psock); } diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index a357dc5f2404..ac1f2bc18fc9 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -213,8 +213,6 @@ static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb) } #endif /* CONFIG_SECURITY_NETWORK */ -#define unix_peer(sk) (unix_sk(sk)->peer) - static inline int unix_our_peer(struct sock *sk, struct sock *osk) { return unix_peer(osk) == sk; diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c index 2f9d8271c6ec..7ea7c3a0d0d0 100644 --- a/net/unix/unix_bpf.c +++ b/net/unix/unix_bpf.c @@ -159,12 +159,17 @@ int unix_dgram_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool re int unix_stream_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore) { + struct sock *sk_pair; + if (restore) { sk->sk_write_space = psock->saved_write_space; sock_replace_proto(sk, psock->sk_proto); return 0; } + sk_pair = unix_peer(sk); + sock_hold(sk_pair); + psock->sk_pair = sk_pair; unix_stream_bpf_check_needs_rebuild(psock->sk_proto); sock_replace_proto(sk, &unix_stream_bpf_prot); return 0; -- cgit v1.2.3