kernel/linux.git/include, branch v6.6.142

string: add mem_is_zero() helper to check if memory area is all zeros

2026-06-01T15:43:15+00:00

[ Upstream commit 3942bb49728ad9e1f94d953a88af169a8f5d8099 ] Almost two thirds of the memchr_inv() usages check if the memory area is all zeros, with no interest in where in the buffer the first non-zero byte is located. Checking for !memchr_inv(s, 0, n) is also not very intuitive or discoverable. Add an explicit mem_is_zero() helper for this use case. Reviewed-by: Kees Cook Reviewed-by: Andy Shevchenko Link: https://patchwork.freedesktop.org/patch/msgid/20240814100035.3100852-1-jani.nikula@intel.com Signed-off-by: Jani Nikula Stable-dep-of: 3e6ccd790ed6 ("gpio: cdev: check if uAPI v2 config attributes are correctly zeroed") Signed-off-by: Sasha Levin

ptrace: Convert ptrace_attach() to use lock guards

2026-06-01T15:43:15+00:00

[ Upstream commit 5431fdd2c181dd2eac218e45b44deb2925fa48f0 ] Created as testing for the conditional guard infrastructure. Specifically this makes use of the following form: scoped_cond_guard (mutex_intr, return -ERESTARTNOINTR, &task->signal->cred_guard_mutex) { ... } ... return 0; Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Oleg Nesterov Link: https://lkml.kernel.org/r/20231102110706.568467727%40infradead.org Stable-dep-of: 60a1969fae62 ("ALSA: seq: Serialize UMP output teardown with event_input") Signed-off-by: Sasha Levin

net: phy: c45: add genphy_c45_pma_read_ext_abilities() function

2026-06-01T15:43:13+00:00

[ Upstream commit 0c476157085fe2ad13b9bec70ea672e86647fa1a ] Move part of the genphy_c45_pma_read_abilities() code to a separate function. Some PHYs do not implement PMA/PMD status 2 register (Register 1.8) but do implement PMA/PMD extended ability register (Register 1.11). To make use of it, we need to be able to access this part of code separately. Signed-off-by: Oleksij Rempel Reviewed-by: Andrew Lunn Reviewed-by: Russell King (Oracle) Link: https://lore.kernel.org/r/20231212054144.87527-2-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski Stable-dep-of: c78bdba7b966 ("net: phy: DP83TC811: add reading of abilities") Signed-off-by: Sasha Levin

kprobes: skip non-symbol addresses in kprobe_add_ksym_blacklist()

2026-06-01T15:43:11+00:00

[ Upstream commit 307abfac04a254c09c5705d816b33354acee97a0 ] When kprobe_add_area_blacklist() iterates through a section like .kprobes.text, the start address may not correspond to a named symbol. On ARM64 with CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS=y (introduced by commit baaf553d3bc3 ("arm64: Implement HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS")), the compiler flag -fpatchable-function-entry=4,2 inserts 2 NOPs before each function entry point for ftrace call_ops. These pre-function NOPs sit at the section base address, before the first named function symbol. The compiler emits a $x mapping symbol at offset 0x00 to mark the start of code, but find_kallsyms_symbol() ignores mapping symbols. Without CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS (e.g. defconfig), no pre-function NOPs are inserted, the first function starts at offset 0x00, and the bug does not trigger. This only affects modules that have a .kprobes.text section (i.e. those using the __kprobes annotation). Modules using NOKPROBE_SYMBOL() instead (like kretprobe_example.ko) blacklist exact function addresses via the _kprobe_blacklist section and are not affected. For kprobe_example.ko on ARM64 with -fpatchable-function-entry=4,2, the .kprobes.text section layout is: offset 0x00: $x + 2 NOPs (mapping symbol + ftrace preamble) offset 0x08: handler_post (64 bytes) offset 0x50: handler_pre (68 bytes) kprobe_add_area_blacklist() starts iterating from the section base address (offset 0x00), which only has the $x mapping symbol. kprobe_add_ksym_blacklist() then calls kallsyms_lookup_size_offset() for this address, which goes through: kallsyms_lookup_size_offset() -> module_address_lookup() -> find_kallsyms_symbol() find_kallsyms_symbol() scans all module symbols to find the closest preceding symbol. Since no named text symbol exists at offset 0x00, find_kallsyms_symbol() picks __UNIQUE_ID_vermagic (a .modinfo symbol whose address is in the temporary image) as the "best" match. The computed "size" = next_text_symbol - modinfo_symbol spans across these two unrelated memory regions, creating a blacklist entry with a bogus range of tens of terabytes. Whether this causes a visible failure depends on address randomization, here is what happens on Raspberry Pi 4/5: - On RPi5, the bogus size was ~35 TB. start + size stayed within 64-bit range, so the blacklist entry covered the entire kernel text. register_kprobe() in the module's own init function failed with -EINVAL. - On RPi4, the bogus size was ~75 TB. start + size overflowed 64 bits and wrapped to a small address near zero. The range check (addr >= start && addr < end) then failed because end wrapped around, so the bogus entry was accidentally harmless and kprobes worked by luck. The same bug exists on both machines, but randomization determines whether the integer overflow masks it or not. Fix this by adding notrace to the __kprobes macro. Functions in .kprobes.text are kprobe infrastructure handlers that should never be traced by ftrace. With notrace, the compiler stops inserting them and the non-symbol gap at the section start disappears entirely. Link: https://lore.kernel.org/all/20260506012706.2785785-1-jianpeng.chang.cn@windriver.com/ Fixes: baaf553d3bc3 ("arm64: Implement HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS") Signed-off-by: Jianpeng Chang Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Sasha Levin

btrfs: tracepoints: fix sleep while in atomic context in btrfs_sync_file()

2026-06-01T15:43:11+00:00

[ Upstream commit c73370c677646e86fc4b1780fb07027bdf847375 ] The trace event btrfs_sync_file() is called in an atomic context (all trace events are) and its call to dput(), which is needed due to the call to dget_parent(), can sleep, triggering a kernel splat. This can be reproduced by enabling the trace event and running btrfs/056 from fstests for example. The splat shown in dmesg is the following: [53.919] BUG: sleeping function called from invalid context at fs/dcache.c:970 [53.947] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 32773, name: xfs_io [53.988] preempt_count: 2, expected: 0 [53.967] RCU nest depth: 0, expected: 0 [53.943] Preemption disabled at: [53.944] [<0000000000000000>] 0x0 [54.078] CPU: 0 UID: 0 PID: 32773 Comm: xfs_io Tainted: G W 7.1.0-rc1-btrfs-next-232+ #1 PREEMPT(full) [54.070] Tainted: [W]=WARN [54.071] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014 [54.072] Call Trace: [54.074] [54.076] dump_stack_lvl+0x56/0x80 [54.079] __might_resched.cold+0xd6/0x10f [54.072] dput.part.0+0x24/0x110 [54.078] trace_event_raw_event_btrfs_sync_file+0x75/0x140 [btrfs] [54.089] btrfs_sync_file+0x1ed/0x530 [btrfs] [54.087] ? __handle_mm_fault+0x8ae/0xed0 [54.089] btrfs_do_write_iter+0x172/0x210 [btrfs] [54.091] vfs_write+0x21f/0x450 [54.094] __x64_sys_pwrite64+0x8d/0xc0 [54.096] ? do_user_addr_fault+0x20c/0x670 [54.099] do_syscall_64+0x60/0xf20 [54.092] ? clear_bhb_loop+0x60/0xb0 [54.094] entry_SYSCALL_64_after_hwframe+0x76/0x7e So stop using dget_parent() and dput() and access the parent dentry directly as dentry->d_parent. This is also what ext4 is doing in its equivalent trace event ext4_sync_file_enter(). Fixes: a85b46db143f ("btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file()") Reviewed-by: Boris Burkov Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

device property: set fwnode->secondary to NULL in fwnode_init()

2026-06-01T15:43:09+00:00

commit 215c90ee656114f5e8c32408228d97082f8e0eef upstream. If a firmware node is allocated on the stack (for instance: temporary software node whose life-time we control) or on the heap - but using a non-zeroing allocation function - and initialized using fwnode_init(), its secondary pointer will contain uninitalized memory which likely will be neither NULL nor IS_ERR() and so may end up being dereferenced (for example: in dev_to_swnode()). Set fwnode->secondary to NULL on initialization. Cc: stable Fixes: 01bb86b380a3 ("driver core: Add fwnode_init()") Signed-off-by: Bartosz Golaszewski Reviewed-by: Rafael J. Wysocki (Intel) Reviewed-by: Andy Shevchenko Reviewed-by: Sakari Ailus Link: https://patch.msgid.link/20260506115701.23035-1-bartosz.golaszewski@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

netfilter: nf_queue: hold bridge skb->dev while queued

2026-06-01T15:43:07+00:00

commit e196115ec330a18de415bdb9f5071aa9f08e53ce upstream. br_pass_frame_up() rewrites skb->dev from the ingress port to the bridge master before queueing bridge LOCAL_IN packets. NFQUEUE only holds references on state.in/out and bridge physdevs, so a queued bridge packet can retain a freed bridge master in skb->dev until reinjection. When the verdict is reinjected later, br_netif_receive_skb() re-enters the receive path with skb->dev still pointing at the freed bridge master, triggering a use-after-free. Store skb->dev in the queue entry, hold a reference on it for the queue lifetime, and use the saved device when dropping queued packets during NETDEV_DOWN handling. Fixes: ac2863445686 ("netfilter: bridge: add nf_afinfo to enable queuing to userspace") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Haoze Xie Signed-off-by: Ren Wei Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

Bluetooth: serialize accept_q access

2026-06-01T15:43:07+00:00

commit e83f5e24da741fa9405aeeff00b08c5ee7c37b88 upstream. bt_sock_poll() walks the accept queue without synchronization, while child teardown can unlink the same socket and drop its last reference. The unsynchronized accept queue walk has existed since the initial Bluetooth import. Protect accept_q with a dedicated lock for queue updates and polling. Also rework bt_accept_dequeue() to take temporary child references under the queue lock before dropping it and locking the child socket. Fixes: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Jann Horn Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Jiexun Wang Signed-off-by: Ren Wei Signed-off-by: Jiexun Wang Reviewed-by: Jann Horn Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

af_unix: Give up GC if MSG_PEEK intervened.

2026-06-01T15:43:05+00:00

[ Upstream commit e5b31d988a41549037b8d8721a3c3cae893d8670 ] Igor Ushakov reported that GC purged the receive queue of an alive socket due to a race with MSG_PEEK with a nice repro. This is the exact same issue previously fixed by commit cbcf01128d0a ("af_unix: fix garbage collect vs MSG_PEEK"). After GC was replaced with the current algorithm, the cited commit removed the locking dance in unix_peek_fds() and reintroduced the same issue. The problem is that MSG_PEEK bumps a file refcount without interacting with GC. Consider an SCC containing sk-A and sk-B, where sk-A is close()d but can be recv()ed via sk-B. The bad thing happens if sk-A is recv()ed with MSG_PEEK from sk-B and sk-B is close()d while GC is checking unix_vertex_dead() for sk-A and sk-B. GC thread User thread --------- ----------- unix_vertex_dead(sk-A) -> true <------. \ `------ recv(sk-B, MSG_PEEK) invalidate !! -> sk-A's file refcount : 1 -> 2 close(sk-B) -> sk-B's file refcount : 2 -> 1 unix_vertex_dead(sk-B) -> true Initially, sk-A's file refcount is 1 by the inflight fd in sk-B recvq. GC thinks sk-A is dead because the file refcount is the same as the number of its inflight fds. However, sk-A's file refcount is bumped silently by MSG_PEEK, which invalidates the previous evaluation. At this moment, sk-B's file refcount is 2; one by the open fd, and one by the inflight fd in sk-A. The subsequent close() releases one refcount by the former. Finally, GC incorrectly concludes that both sk-A and sk-B are dead. One option is to restore the locking dance in unix_peek_fds(), but we can resolve this more elegantly thanks to the new algorithm. The point is that the issue does not occur without the subsequent close() and we actually do not need to synchronise MSG_PEEK with the dead SCC detection. When the issue occurs, close() and GC touch the same file refcount. If GC sees the refcount being decremented by close(), it can just give up garbage-collecting the SCC. Therefore, we only need to signal the race during MSG_PEEK with a proper memory barrier to make it visible to the GC. Let's use seqcount_t to notify GC when MSG_PEEK occurs and let it defer the SCC to the next run. This way no locking is needed on the MSG_PEEK side, and we can avoid imposing a penalty on every MSG_PEEK unnecessarily. Note that we can retry within unix_scc_dead() if MSG_PEEK is detected, but we do not do so to avoid hung task splat from abusive MSG_PEEK calls. Fixes: 118f457da9ed ("af_unix: Remove lock dance in unix_peek_fds().") Reported-by: Igor Ushakov Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260311054043.1231316-1-kuniyu@google.com Signed-off-by: Jakub Kicinski [ Using include/net/af_unix.h instead of net/unix/af_unix.h on 6.6 ] Signed-off-by: Leon Chen Signed-off-by: Sasha Levin

driver core: platform: use generic driver_override infrastructure

2026-06-01T15:43:04+00:00

[ Upstream commit 2b38efc05bf7a8568ec74bfffea0f5cfa62bc01d ] When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260303115720.48783-5-dakr@kernel.org Signed-off-by: Danilo Krummrich Signed-off-by: Sasha Levin Signed-off-by: David Sauerwein Signed-off-by: Sasha Levin