From ff917923f4fb9c83717ba135ee47d7e4c1567bb7 Mon Sep 17 00:00:00 2001 From: Muhammad Bilal Date: Tue, 28 Jul 2026 17:54:55 +0500 Subject: staging: rtl8723bs: fix OOB read in rtw_action_frame_parse() rtw_action_frame_parse() takes a frame_len parameter but never actually checks it before indexing into the frame body: const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr); ... c = frame_body[0]; ... a = frame_body[1]; frame_body already points 24 bytes (sizeof(struct ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and frame_body[1] requires frame_len >= 26. A management action frame shorter than that (e.g. exactly 24 bytes, the minimum a malicious peer can send) causes a 1-2 byte out-of-bounds read. This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass attacker/user-influenced frame buffers and lengths straight through. Add the missing length check before frame_body is dereferenced. Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com Signed-off-by: Greg Kroah-Hartman --- fs/ceph/io.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 213 insertions(+) create mode 100644 fs/ceph/io.c (limited to 'fs/ceph/io.c') diff --git a/fs/ceph/io.c b/fs/ceph/io.c new file mode 100644 index 000000000..2d10f49c9 --- /dev/null +++ b/fs/ceph/io.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2016 Trond Myklebust + * Copyright (c) 2019 Jeff Layton + * + * I/O and data path helper functionality. + * + * Heavily borrowed from equivalent code in fs/nfs/io.c + */ + +#include + +#include +#include +#include +#include + +#include "super.h" +#include "io.h" + +/* Call with exclusively locked inode->i_rwsem */ +static void ceph_block_o_direct(struct ceph_inode_info *ci, struct inode *inode) +{ + bool is_odirect; + + lockdep_assert_held_write(&inode->i_rwsem); + + spin_lock(&ci->i_ceph_lock); + /* ensure that bit state is consistent */ + smp_mb__before_atomic(); + is_odirect = READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT; + if (is_odirect) { + clear_bit(CEPH_I_ODIRECT_BIT, &ci->i_ceph_flags); + /* ensure modified bit is visible */ + smp_mb__after_atomic(); + } + spin_unlock(&ci->i_ceph_lock); + + if (is_odirect) + inode_dio_wait(inode); +} + +/** + * ceph_start_io_read - declare the file is being used for buffered reads + * @inode: file inode + * + * Declare that a buffered read operation is about to start, and ensure + * that we block all direct I/O. + * On exit, the function ensures that the CEPH_I_ODIRECT flag is unset, + * and holds a shared lock on inode->i_rwsem to ensure that the flag + * cannot be changed. + * In practice, this means that buffered read operations are allowed to + * execute in parallel, thanks to the shared lock, whereas direct I/O + * operations need to wait to grab an exclusive lock in order to set + * CEPH_I_ODIRECT. + * Note that buffered writes and truncates both take a write lock on + * inode->i_rwsem, meaning that those are serialised w.r.t. the reads. + */ +int ceph_start_io_read(struct inode *inode) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + bool is_odirect; + int err; + + /* Be an optimist! */ + err = down_read_killable(&inode->i_rwsem); + if (err) + return err; + + spin_lock(&ci->i_ceph_lock); + /* ensure that bit state is consistent */ + smp_mb__before_atomic(); + is_odirect = READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT; + spin_unlock(&ci->i_ceph_lock); + if (!is_odirect) + return 0; + up_read(&inode->i_rwsem); + + /* Slow path.... */ + err = down_write_killable(&inode->i_rwsem); + if (err) + return err; + + ceph_block_o_direct(ci, inode); + downgrade_write(&inode->i_rwsem); + + return 0; +} + +/** + * ceph_end_io_read - declare that the buffered read operation is done + * @inode: file inode + * + * Declare that a buffered read operation is done, and release the shared + * lock on inode->i_rwsem. + */ +void +ceph_end_io_read(struct inode *inode) +{ + up_read(&inode->i_rwsem); +} + +/** + * ceph_start_io_write - declare the file is being used for buffered writes + * @inode: file inode + * + * Declare that a buffered write operation is about to start, and ensure + * that we block all direct I/O. + */ +int ceph_start_io_write(struct inode *inode) +{ + int err = down_write_killable(&inode->i_rwsem); + if (!err) + ceph_block_o_direct(ceph_inode(inode), inode); + return err; +} + +/** + * ceph_end_io_write - declare that the buffered write operation is done + * @inode: file inode + * + * Declare that a buffered write operation is done, and release the + * lock on inode->i_rwsem. + */ +void +ceph_end_io_write(struct inode *inode) +{ + up_write(&inode->i_rwsem); +} + +/* Call with exclusively locked inode->i_rwsem */ +static void ceph_block_buffered(struct ceph_inode_info *ci, struct inode *inode) +{ + bool is_odirect; + + lockdep_assert_held_write(&inode->i_rwsem); + + spin_lock(&ci->i_ceph_lock); + /* ensure that bit state is consistent */ + smp_mb__before_atomic(); + is_odirect = READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT; + if (!is_odirect) { + set_bit(CEPH_I_ODIRECT_BIT, &ci->i_ceph_flags); + /* ensure modified bit is visible */ + smp_mb__after_atomic(); + } + spin_unlock(&ci->i_ceph_lock); + + if (!is_odirect) { + /* FIXME: unmap_mapping_range? */ + filemap_write_and_wait(inode->i_mapping); + } +} + +/** + * ceph_start_io_direct - declare the file is being used for direct i/o + * @inode: file inode + * + * Declare that a direct I/O operation is about to start, and ensure + * that we block all buffered I/O. + * On exit, the function ensures that the CEPH_I_ODIRECT flag is set, + * and holds a shared lock on inode->i_rwsem to ensure that the flag + * cannot be changed. + * In practice, this means that direct I/O operations are allowed to + * execute in parallel, thanks to the shared lock, whereas buffered I/O + * operations need to wait to grab an exclusive lock in order to clear + * CEPH_I_ODIRECT. + * Note that buffered writes and truncates both take a write lock on + * inode->i_rwsem, meaning that those are serialised w.r.t. O_DIRECT. + */ +int ceph_start_io_direct(struct inode *inode) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + bool is_odirect; + int err; + + /* Be an optimist! */ + err = down_read_killable(&inode->i_rwsem); + if (err) + return err; + + spin_lock(&ci->i_ceph_lock); + /* ensure that bit state is consistent */ + smp_mb__before_atomic(); + is_odirect = READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT; + spin_unlock(&ci->i_ceph_lock); + if (is_odirect) + return 0; + up_read(&inode->i_rwsem); + + /* Slow path.... */ + err = down_write_killable(&inode->i_rwsem); + if (err) + return err; + + ceph_block_buffered(ci, inode); + downgrade_write(&inode->i_rwsem); + + return 0; +} + +/** + * ceph_end_io_direct - declare that the direct i/o operation is done + * @inode: file inode + * + * Declare that a direct I/O operation is done, and release the shared + * lock on inode->i_rwsem. + */ +void +ceph_end_io_direct(struct inode *inode) +{ + up_read(&inode->i_rwsem); +} -- cgit v1.3.1