/* * Copyright (C) 2011 Fujitsu. All rights reserved. * Written by Miao Xie * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #ifndef __DELAYED_TREE_OPERATION_H #define __DELAYED_TREE_OPERATION_H #include #include #include #include #include #include #include "ctree.h" /* types of the delayed item */ #define BTRFS_DELAYED_INSERTION_ITEM 1 #define BTRFS_DELAYED_DELETION_ITEM 2 struct btrfs_delayed_root { spinlock_t lock; struct list_head node_list; /* * Used for delayed nodes which is waiting to be dealt with by the * worker. If the delayed node is inserted into the work queue, we * drop it from this list. */ struct list_head prepare_list; atomic_t items; /* for delayed items */ atomic_t items_seq; /* for delayed items */ int nodes; /* for delayed nodes */ wait_queue_head_t wait; }; #define BTRFS_DELAYED_NODE_IN_LIST 0 #define BTRFS_DELAYED_NODE_INODE_DIRTY 1 #define BTRFS_DELAYED_NODE_DEL_IREF 2 struct btrfs_delayed_node { u64 inode_id; u64 bytes_reserved; struct btrfs_root *root; /* Used to add the node into the delayed root's node list. */ struct list_head n_list; /* * Used to add the node into the prepare list, the nodes in this list * is waiting to be dealt with by the async worker. */ struct list_head p_list; struct rb_root ins_root; struct rb_root del_root; struct mutex mutex; struct btrfs_inode_item inode_item; atomic_t refs; u64 index_cnt; unsigned long flags; int count; }; struct btrfs_delayed_item { struct rb_node rb_node; struct btrfs_key key; struct list_head tree_list; /* used for batch insert/delete items */ struct list_head readdir_list; /* used for readdir items */ u64 bytes_reserved; struct btrfs_delayed_node *delayed_node; atomic_t refs; int ins_or_del; u32 data_len; char data[0]; }; static inline void btrfs_init_delayed_root( struct btrfs_delayed_root *delayed_root) { atomic_set(&delayed_root->items, 0); atomic_set(&delayed_root->items_seq, 0); delayed_root->nodes = 0; spin_lock_init(&delayed_root->lock); init_waitqueue_head(&delayed_root->wait); INIT_LIST_HEAD(&delayed_root->node_list); INIT_LIST_HEAD(&delayed_root->prepare_list); } int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, const char *name, int name_len, struct inode *dir, struct btrfs_disk_key *disk_key, u8 type, u64 index); int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, struct inode *dir, u64 index); int btrfs_inode_delayed_dir_index_count(struct inode *inode); int btrfs_run_delayed_items(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info); int btrfs_run_delayed_items_nr(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, int nr); void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info); int btrfs_commit_inode_delayed_items(struct btrfs_trans_handle *trans, struct inode *inode); /* Used for evicting the inode. */ void btrfs_remove_delayed_node(struct inode *inode); void btrfs_kill_delayed_inode_items(struct inode *inode); int btrfs_commit_inode_delayed_inode(struct inode *inode); int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode); int btrfs_fill_inode(struct inode *inode, u32 *rdev); int btrfs_delayed_delete_inode_ref(struct inode *inode); /* Used for drop dead root */ void btrfs_kill_all_delayed_nodes(struct btrfs_root *root); /* Used for clean the transaction */ void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info); /* Used for readdir() */ bool btrfs_readdir_get_delayed_items(struct inode *inode, struct list_head *ins_list, struct list_head *del_list); void btrfs_readdir_put_delayed_items(struct inode *inode, struct list_head *ins_list, struct list_head *del_list); int btrfs_should_delete_dir_index(struct list_head *del_list, u64 index); int btrfs_readdir_delayed_dir_index(struct dir_context *ctx, struct list_head *ins_list); /* for init */ int __init btrfs_delayed_inode_init(void); void btrfs_delayed_inode_exit(void); /* for debugging */ void btrfs_assert_delayed_root_empty(struct btrfs_fs_info *fs_info); #endif >191e885a2e130e639bb0c8ee350d7047294f2ce6 (patch) tree9bf9f9b4971df55a46e0a6750d3f6cd37bf1d9f0 /sound/soc/codecs/isabelle.c parent49def1853334396f948dcb4cedb9347abb318df5 (diff)
firmware: fix NULL pointer dereference in __fw_load_abort()
Since commit 5d47ec02c37ea6 ("firmware: Correct handling of fw_state_wait() return value") fw_load_abort() could be called twice and lead us to a kernel crash. This happens only when the firmware fallback mechanism (regular or custom) is used. The fallback mechanism exposes a sysfs interface for userspace to upload a file and notify the kernel when the file is loaded and ready, or to cancel an upload by echo'ing -1 into on the loading file: echo -n "-1" > /sys/$DEVPATH/loading This will call fw_load_abort(). Some distributions actually have a udev rule in place to *always* immediately cancel all firmware fallback mechanism requests (Debian), they have: $ cat /lib/udev/rules.d/50-firmware.rules # stub for immediately telling the kernel that userspace firmware loading # failed; necessary to avoid long timeouts with CONFIG_FW_LOADER_USER_HELPER=y SUBSYSTEM=="firmware", ACTION=="add", ATTR{loading}="-1 Distributions with this udev rule would run into this crash only if the fallback mechanism is used. Since most distributions disable by default using the fallback mechanism (CONFIG_FW_LOADER_USER_HELPER_FALLBACK), this would typicaly mean only 2 drivers which *require* the fallback mechanism could typically incur a crash: drivers/firmware/dell_rbu.c and the drivers/leds/leds-lp55xx-common.c driver. Distributions enabling CONFIG_FW_LOADER_USER_HELPER_FALLBACK by default are obviously more exposed to this crash. The crash happens because after commit 5b029624948d ("firmware: do not use fw_lock for fw_state protection") and subsequent fix commit 5d47ec02c37ea6 ("firmware: Correct handling of fw_state_wait() return value") a race can happen between this cancelation and the firmware fw_state_wait_timeout() being woken up after a state change with which fw_load_abort() as that calls swake_up(). Upon error fw_state_wait_timeout() will also again call fw_load_abort() and trigger a null reference. At first glance we could just fix this with a !buf check on fw_load_abort() before accessing buf->fw_st, however there is a logical issue in having a state machine used for the fallback mechanism and preventing access from it once we abort as its inside the buf (buf->fw_st). The firmware_class.c code is setting the buf to NULL to annotate an abort has occurred. Replace this mechanism by simply using the state check instead. All the other code in place already uses similar checks for aborting as well so no further changes are needed. An oops can be reproduced with the new fw_fallback.sh fallback mechanism cancellation test. Either cancelling the fallback mechanism or the custom fallback mechanism triggers a crash. mcgrof@piggy ~/linux-next/tools/testing/selftests/firmware (git::20170111-fw-fixes)$ sudo ./fw_fallback.sh ./fw_fallback.sh: timeout works ./fw_fallback.sh: firmware comparison works ./fw_fallback.sh: fallback mechanism works [ this then sits here when it is trying the cancellation test ] Kernel log: test_firmware: loading 'nope-test-firmware.bin' misc test_firmware: Direct firmware load for nope-test-firmware.bin failed with error -2 misc test_firmware: Falling back to user helper BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 IP: _request_firmware+0xa27/0xad0 PGD 0 Oops: 0000 [#1] SMP Modules linked in: test_firmware(E) ... etc ... CPU: 1 PID: 1396 Comm: fw_fallback.sh Tainted: G W E 4.10.0-rc3-next-20170111+ #30 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014 task: ffff9740b27f4340 task.stack: ffffbb15c0bc8000 RIP: 0010:_request_firmware+0xa27/0xad0 RSP: 0018:ffffbb15c0bcbd10 EFLAGS: 00010246 RAX: 00000000fffffffe RBX: ffff9740afe5aa80 RCX: 0000000000000000 RDX: ffff9740b27f4340 RSI: 0000000000000283 RDI: 0000000000000000 RBP: ffffbb15c0bcbd90 R08: ffffbb15c0bcbcd8 R09: 0000000000000000 R10: 0000000894a0d4b1 R11: 000000000000008c R12: ffffffffc0312480 R13: 0000000000000005 R14: ffff9740b1c32400 R15: 00000000000003e8 FS: 00007f8604422700(0000) GS:ffff9740bfc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000038 CR3: 000000012164c000 CR4: 00000000000006e0 Call Trace: request_firmware+0x37/0x50 trigger_request_store+0x79/0xd0 [test_firmware] dev_attr_store+0x18/0x30 sysfs_kf_write+0x37/0x40 kernfs_fop_write+0x110/0x1a0 __vfs_write+0x37/0x160 ? _cond_resched+0x1a/0x50 vfs_write+0xb5/0x1a0 SyS_write+0x55/0xc0 ? trace_do_page_fault+0x37/0xd0 entry_SYSCALL_64_fastpath+0x1e/0xad RIP: 0033:0x7f8603f49620 RSP: 002b:00007fff6287b788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055c307b110a0 RCX: 00007f8603f49620 RDX: 0000000000000016 RSI: 000055c3084d8a90 RDI: 0000000000000001 RBP: 0000000000000016 R08: 000000000000c0ff R09: 000055c3084d6336 R10: 000055c307b108b0 R11: 0000000000000246 R12: 000055c307b13c80 R13: 000055c3084d6320 R14: 0000000000000000 R15: 00007fff6287b950 Code: 9f 64 84 e8 9c 61 fe ff b8 f4 ff ff ff e9 6b f9 ff ff 48 c7 c7 40 6b 8d 84 89 45 a8 e8 43 84 18 00 49 8b be 00 03 00 00 8b 45 a8 <83> 7f 38 02 74 08 e8 6e ec ff ff 8b 45 a8 49 c7 86 00 03 00 00 RIP: _request_firmware+0xa27/0xad0 RSP: ffffbb15c0bcbd10 CR2: 0000000000000038 ---[ end trace 6d94ac339c133e6f ]--- Fixes: 5d47ec02c37e ("firmware: Correct handling of fw_state_wait() return value") Reported-and-Tested-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reported-and-Tested-by: Patrick Bruenn <p.bruenn@beckhoff.com> Reported-by: Chris Wilson <chris@chris-wilson.co.uk> CC: <stable@vger.kernel.org> [3.10+] Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound/soc/codecs/isabelle.c')