kernel/linux.git/init, branch v6.6.131

init: handle bootloader identifier in kernel parameters

2025-10-19T14:30:50+00:00

commit e416f0ed3c500c05c55fb62ee62662717b1c7f71 upstream. BootLoaders (Grub, LILO, etc) may pass an identifier such as "BOOT_IMAGE= /boot/vmlinuz-x.y.z" to kernel parameters. But these identifiers are not recognized by the kernel itself so will be passed to userspace. However user space init program also don't recognize it. KEXEC/KDUMP (kexec-tools) may also pass an identifier such as "kexec" on some architectures. We cannot change BootLoader's behavior, because this behavior exists for many years, and there are already user space programs search BOOT_IMAGE= in /proc/cmdline to obtain the kernel image locations: https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/util.go (search getBootOptions) https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/main.go (search getKernelReleaseWithBootOption) So the the best way is handle (ignore) it by the kernel itself, which can avoid such boot warnings (if we use something like init=/bin/bash, bootloader identifier can even cause a crash): Kernel command line: BOOT_IMAGE=(hd0,1)/vmlinuz-6.x root=/dev/sda3 ro console=tty Unknown kernel command line parameters "BOOT_IMAGE=(hd0,1)/vmlinuz-6.x", will be passed to user space. [chenhuacai@loongson.cn: use strstarts()] Link: https://lkml.kernel.org/r/20250815090120.1569947-1-chenhuacai@loongson.cn Link: https://lkml.kernel.org/r/20250721101343.3283480-1-chenhuacai@loongson.cn Signed-off-by: Huacai Chen Cc: Al Viro Cc: Christian Brauner Cc: Jan Kara Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

init: INITRAMFS_PRESERVE_MTIME should depend on BLK_DEV_INITRD

2025-10-15T09:57:48+00:00

[ Upstream commit 74792608606a525a0e0df7e8d48acd8000561389 ] INITRAMFS_PRESERVE_MTIME is only used in init/initramfs.c and init/initramfs_test.c. Hence add a dependency on BLK_DEV_INITRD, to prevent asking the user about this feature when configuring a kernel without initramfs support. Fixes: 1274aea127b2e8c9 ("initramfs: add INITRAMFS_PRESERVE_MTIME Kconfig option") Signed-off-by: Geert Uytterhoeven Reviewed-by: Martin Wilck Reviewed-by: David Disseldorp Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

sched/isolation: Make CONFIG_CPU_ISOLATION depend on CONFIG_SMP

2025-05-02T05:50:57+00:00

[ Upstream commit 975776841e689dd8ba36df9fa72ac3eca3c2957a ] kernel/sched/isolation.c obviously makes no sense without CONFIG_SMP, but the Kconfig entry we have right now: config CPU_ISOLATION bool "CPU isolation" depends on SMP || COMPILE_TEST allows the creation of pointless .config's which cause build failures. Reported-by: kernel test robot Signed-off-by: Oleg Nesterov Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250330134955.GA7910@redhat.com Closes: https://lore.kernel.org/oe-kbuild-all/202503260646.lrUqD3j5-lkp@intel.com/ Signed-off-by: Sasha Levin

rust: Disallow BTF generation with Rust + LTO

2025-03-22T19:50:48+00:00

commit 5daa0c35a1f0e7a6c3b8ba9cb721e7d1ace6e619 upstream. The kernel cannot currently self-parse BTF containing Rust debug information. pahole uses the language of the CU to determine whether to filter out debug information when generating the BTF. When LTO is enabled, Rust code can cross CU boundaries, resulting in Rust debug information in CUs labeled as C. This results in a system which cannot parse its own BTF. Signed-off-by: Matthew Maurer Cc: stable@vger.kernel.org Fixes: c1177979af9c ("btf, scripts: Exclude Rust CUs with pahole") Link: https://lore.kernel.org/r/20250108-rust-btf-lto-incompat-v1-1-60243ff6d820@google.com Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

Compiler Attributes: disable __counted_by for clang < 19.1.3

2024-12-09T09:32:46+00:00

commit f06e108a3dc53c0f5234d18de0bd224753db5019 upstream. This patch disables __counted_by for clang versions < 19.1.3 because of the two issues listed below. It does this by introducing CONFIG_CC_HAS_COUNTED_BY. 1. clang < 19.1.2 has a bug that can lead to __bdos returning 0: https://github.com/llvm/llvm-project/pull/110497 2. clang < 19.1.3 has a bug that can lead to __bdos being off by 4: https://github.com/llvm/llvm-project/pull/112636 Fixes: c8248faf3ca2 ("Compiler Attributes: counted_by: Adjust name and identifier expansion") Cc: stable@vger.kernel.org # 6.6.x: 16c31dd7fdf6: Compiler Attributes: counted_by: bump min gcc version Cc: stable@vger.kernel.org # 6.6.x: 2993eb7a8d34: Compiler Attributes: counted_by: fixup clang URL Cc: stable@vger.kernel.org # 6.6.x: 231dc3f0c936: lkdtm/bugs: Improve warning message for compilers without counted_by support Cc: stable@vger.kernel.org # 6.6.x Reported-by: Nathan Chancellor Closes: https://lore.kernel.org/all/20240913164630.GA4091534@thelio-3990X/ Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202409260949.a1254989-oliver.sang@intel.com Link: https://lore.kernel.org/all/Zw8iawAF5W2uzGuh@archlinux/T/#m204c09f63c076586a02d194b87dffc7e81b8de7b Suggested-by: Nathan Chancellor Signed-off-by: Jan Hendrik Farr Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Reviewed-by: Miguel Ojeda Reviewed-by: Thorsten Blum Link: https://lore.kernel.org/r/20241029140036.577804-2-kernel@jfarr.cc Signed-off-by: Kees Cook Signed-off-by: Jan Hendrik Farr Signed-off-by: Greg Kroah-Hartman

initramfs: avoid filename buffer overrun

2024-12-09T09:31:44+00:00

[ Upstream commit e017671f534dd3f568db9e47b0583e853d2da9b5 ] The initramfs filename field is defined in Documentation/driver-api/early-userspace/buffer-format.rst as: 37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data ... 55 ============= ================== ========================= 56 Field name Field size Meaning 57 ============= ================== ========================= ... 70 c_namesize 8 bytes Length of filename, including final \0 When extracting an initramfs cpio archive, the kernel's do_name() path handler assumes a zero-terminated path at @collected, passing it directly to filp_open() / init_mkdir() / init_mknod(). If a specially crafted cpio entry carries a non-zero-terminated filename and is followed by uninitialized memory, then a file may be created with trailing characters that represent the uninitialized memory. The ability to create an initramfs entry would imply already having full control of the system, so the buffer overrun shouldn't be considered a security vulnerability. Append the output of the following bash script to an existing initramfs and observe any created /initramfs_test_fname_overrunAA* path. E.g. ./reproducer.sh | gzip >> /myinitramfs It's easiest to observe non-zero uninitialized memory when the output is gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(), rather than the initrd_start+initrd_size block. ---- reproducer.sh ---- nilchar="A" # change to "\0" to properly zero terminate / pad magic="070701" ino=1 mode=$(( 0100777 )) uid=0 gid=0 nlink=1 mtime=1 filesize=0 devmajor=0 devminor=1 rdevmajor=0 rdevminor=0 csum=0 fname="initramfs_test_fname_overrun" namelen=$(( ${#fname} + 1 )) # plus one to account for terminator printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \ $magic $ino $mode $uid $gid $nlink $mtime $filesize \ $devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname termpadlen=$(( 1 + ((4 - ((110 + $namelen) & 3)) % 4) )) printf "%.s${nilchar}" $(seq 1 $termpadlen) ---- reproducer.sh ---- Symlink filename fields handled in do_symlink() won't overrun past the data segment, due to the explicit zero-termination of the symlink target. Fix filename buffer overrun by aborting the initramfs FSM if any cpio entry doesn't carry a zero-terminator at the expected (name_len - 1) offset. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: David Disseldorp Link: https://lore.kernel.org/r/20241030035509.20194-2-ddiss@suse.de Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

rcu-tasks: Initialize data to eliminate RCU-tasks/do_exit() deadlocks

2024-11-08T15:28:22+00:00

[ Upstream commit 46faf9d8e1d52e4a91c382c6c72da6bd8e68297b ] Holding a mutex across synchronize_rcu_tasks() and acquiring that same mutex in code called from do_exit() after its call to exit_tasks_rcu_start() but before its call to exit_tasks_rcu_stop() results in deadlock. This is by design, because tasks that are far enough into do_exit() are no longer present on the tasks list, making it a bit difficult for RCU Tasks to find them, let alone wait on them to do a voluntary context switch. However, such deadlocks are becoming more frequent. In addition, lockdep currently does not detect such deadlocks and they can be difficult to reproduce. In addition, if a task voluntarily context switches during that time (for example, if it blocks acquiring a mutex), then this task is in an RCU Tasks quiescent state. And with some adjustments, RCU Tasks could just as well take advantage of that fact. This commit therefore initializes the data structures that will be needed to rely on these quiescent states and to eliminate these deadlocks. Link: https://lore.kernel.org/all/20240118021842.290665-1-chenzhongjin@huawei.com/ Reported-by: Chen Zhongjin Reported-by: Yang Jihong Signed-off-by: Paul E. McKenney Tested-by: Yang Jihong Tested-by: Chen Zhongjin Reviewed-by: Frederic Weisbecker Signed-off-by: Boqun Feng Stable-dep-of: fd70e9f1d85f ("rcu-tasks: Fix access non-existent percpu rtpcp variable in rcu_tasks_need_gpcb()") Signed-off-by: Sasha Levin

rust: fix the default format for CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT

2024-08-29T15:33:29+00:00

[ Upstream commit aacf93e87f0d808ef46e621aa56caea336b4433c ] Another oddity in these config entries is their default value can fall back to 'n', which is a value for bool or tristate symbols. The '|| echo n' is an incorrect workaround to avoid the syntax error. This is not a big deal, as the entry is hidden by 'depends on RUST' in situations where '$(RUSTC) --version' or '$(BINDGEN) --version' fails. Anyway, it looks odd. The default of a string type symbol should be a double-quoted string literal. Turn it into an empty string when the version command fails. Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support") Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240727140302.1806011-2-masahiroy@kernel.org [ Rebased on top of v6.11-rc1. - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT

2024-08-29T15:33:29+00:00

[ Upstream commit 5ce86c6c861352c9346ebb5c96ed70cb67414aa3 ] While this is a somewhat unusual case, I encountered odd error messages when I ran Kconfig in a foreign architecture chroot. $ make allmodconfig sh: 1: rustc: not found sh: 1: bindgen: not found # # configuration written to .config # The successful execution of 'command -v rustc' does not necessarily mean that 'rustc --version' will succeed. $ sh -c 'command -v rustc' /home/masahiro/.cargo/bin/rustc $ sh -c 'rustc --version' sh: 1: rustc: not found Here, 'rustc' is built for x86, and I ran it in an arm64 system. The current code: command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n can be turned into: command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version 2>/dev/null || echo n However, I did not understand the necessity of 'command -v $(RUSTC)'. I simplified it to: $(RUSTC) --version 2>/dev/null || echo n Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support") Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240727140302.1806011-1-masahiroy@kernel.org [ Rebased on top of v6.11-rc1. - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

rust: work around `bindgen` 0.69.0 issue

2024-08-29T15:33:29+00:00

[ Upstream commit 9e98db17837093cb0f4dcfcc3524739d93249c45 ] `bindgen` 0.69.0 contains a bug: `--version` does not work without providing a header [1]: error: the following required arguments were not provided:

Usage: bindgen

-- ... Thus, in preparation for supporting several `bindgen` versions, work around the issue by passing a dummy argument. Include a comment so that we can remove the workaround in the future. Link: https://github.com/rust-lang/rust-bindgen/pull/2678 [1] Reviewed-by: Finn Behrens Tested-by: Benno Lossin Tested-by: Andreas Hindborg Link: https://lore.kernel.org/r/20240709160615.998336-9-ojeda@kernel.org Signed-off-by: Miguel Ojeda Stable-dep-of: 5ce86c6c8613 ("rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT") Signed-off-by: Sasha Levin