From d3bdf70cf0e862d7f1641522c32e55764cd5b481 Mon Sep 17 00:00:00 2001 From: Hemanth Selam Date: Fri, 4 Sep 2026 16:48:14 +0530 Subject: driver core: fix typos in comments Fix typos in comments, reported by scripts/checkpatch.pl using the misspelling list in scripts/spelling.txt. Only touches comments, no code changes. Assisted-by: LLM Signed-off-by: Hemanth Selam Reviewed-by: Andy Shevchenko Acked-by: Randy Dunlap Link: https://patch.msgid.link/20260904111816.31254-1-hemanth.selam@gmail.com Signed-off-by: Danilo Krummrich --- include/linux/kernfs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 351a5101c862..73786b567ccd 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -309,7 +309,7 @@ struct kernfs_ops { * write() is bounced through kernel buffer. If atomic_write_len * is not set, a write larger than PAGE_SIZE results in partial * operations of PAGE_SIZE chunks. If atomic_write_len is set, - * writes upto the specified size are executed atomically but + * writes up to the specified size are executed atomically but * larger ones are rejected with -E2BIG. */ size_t atomic_write_len; -- cgit v1.2.3 From ae324a719289a66197762ee3e78fec5dea144ba7 Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Mon, 7 Sep 2026 07:45:03 +0200 Subject: driver core: Constify the signature of device_show/store_*() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Prepare for the constification of 'struct dev_ext_attribute' by changing the signature of the standard callback functions. Migrate the hv-24x7 driver in the same commit. It is the only user to manually assign one of the standard callbacks. Signed-off-by: Thomas Weißschuh Link: https://patch.msgid.link/20260907-sysfs-const-attr-dev_ext_attr-v2-3-bf53afe57071@weissschuh.net Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/perf/hv-24x7.c | 2 +- drivers/base/core.c | 30 +++++++++++++++--------------- include/linux/device.h | 14 +++++++------- 3 files changed, 23 insertions(+), 23 deletions(-) (limited to 'include/linux') diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c index b0eedf185960..3e094dc7d76b 100644 --- a/arch/powerpc/perf/hv-24x7.c +++ b/arch/powerpc/perf/hv-24x7.c @@ -462,7 +462,7 @@ static struct attribute *device_str_attr_create_(char *name, char *str) attr->var = str; attr->attr.attr.name = name; attr->attr.attr.mode = 0444; - attr->attr.show = device_show_string; + attr->attr.show_const = device_show_string; return &attr->attr.attr; } diff --git a/drivers/base/core.c b/drivers/base/core.c index 4c0c373998a1..5daa88fa724a 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2517,13 +2517,13 @@ static const struct sysfs_ops dev_sysfs_ops = { .store = dev_attr_store, }; -#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr) +#define to_ext_attr(x) container_of_const(x, struct dev_ext_attribute, attr) ssize_t device_store_ulong(struct device *dev, - struct device_attribute *attr, + const struct device_attribute *attr, const char *buf, size_t size) { - struct dev_ext_attribute *ea = to_ext_attr(attr); + const struct dev_ext_attribute *ea = to_ext_attr(attr); int ret; unsigned long new; @@ -2537,19 +2537,19 @@ ssize_t device_store_ulong(struct device *dev, EXPORT_SYMBOL_GPL(device_store_ulong); ssize_t device_show_ulong(struct device *dev, - struct device_attribute *attr, + const struct device_attribute *attr, char *buf) { - struct dev_ext_attribute *ea = to_ext_attr(attr); + const struct dev_ext_attribute *ea = to_ext_attr(attr); return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var)); } EXPORT_SYMBOL_GPL(device_show_ulong); ssize_t device_store_int(struct device *dev, - struct device_attribute *attr, + const struct device_attribute *attr, const char *buf, size_t size) { - struct dev_ext_attribute *ea = to_ext_attr(attr); + const struct dev_ext_attribute *ea = to_ext_attr(attr); int ret; long new; @@ -2566,19 +2566,19 @@ ssize_t device_store_int(struct device *dev, EXPORT_SYMBOL_GPL(device_store_int); ssize_t device_show_int(struct device *dev, - struct device_attribute *attr, + const struct device_attribute *attr, char *buf) { - struct dev_ext_attribute *ea = to_ext_attr(attr); + const struct dev_ext_attribute *ea = to_ext_attr(attr); return sysfs_emit(buf, "%d\n", *(int *)(ea->var)); } EXPORT_SYMBOL_GPL(device_show_int); -ssize_t device_store_bool(struct device *dev, struct device_attribute *attr, +ssize_t device_store_bool(struct device *dev, const struct device_attribute *attr, const char *buf, size_t size) { - struct dev_ext_attribute *ea = to_ext_attr(attr); + const struct dev_ext_attribute *ea = to_ext_attr(attr); if (kstrtobool(buf, ea->var) < 0) return -EINVAL; @@ -2587,19 +2587,19 @@ ssize_t device_store_bool(struct device *dev, struct device_attribute *attr, } EXPORT_SYMBOL_GPL(device_store_bool); -ssize_t device_show_bool(struct device *dev, struct device_attribute *attr, +ssize_t device_show_bool(struct device *dev, const struct device_attribute *attr, char *buf) { - struct dev_ext_attribute *ea = to_ext_attr(attr); + const struct dev_ext_attribute *ea = to_ext_attr(attr); return sysfs_emit(buf, "%d\n", *(bool *)(ea->var)); } EXPORT_SYMBOL_GPL(device_show_bool); ssize_t device_show_string(struct device *dev, - struct device_attribute *attr, char *buf) + const struct device_attribute *attr, char *buf) { - struct dev_ext_attribute *ea = to_ext_attr(attr); + const struct dev_ext_attribute *ea = to_ext_attr(attr); return sysfs_emit(buf, "%s\n", (char *)ea->var); } diff --git a/include/linux/device.h b/include/linux/device.h index aee79fd6b32b..90cdd77458bb 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -129,19 +129,19 @@ struct dev_ext_attribute { void *var; }; -ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr, +ssize_t device_show_ulong(struct device *dev, const struct device_attribute *attr, char *buf); -ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr, +ssize_t device_store_ulong(struct device *dev, const struct device_attribute *attr, const char *buf, size_t count); -ssize_t device_show_int(struct device *dev, struct device_attribute *attr, +ssize_t device_show_int(struct device *dev, const struct device_attribute *attr, char *buf); -ssize_t device_store_int(struct device *dev, struct device_attribute *attr, +ssize_t device_store_int(struct device *dev, const struct device_attribute *attr, const char *buf, size_t count); -ssize_t device_show_bool(struct device *dev, struct device_attribute *attr, +ssize_t device_show_bool(struct device *dev, const struct device_attribute *attr, char *buf); -ssize_t device_store_bool(struct device *dev, struct device_attribute *attr, +ssize_t device_store_bool(struct device *dev, const struct device_attribute *attr, const char *buf, size_t count); -ssize_t device_show_string(struct device *dev, struct device_attribute *attr, +ssize_t device_show_string(struct device *dev, const struct device_attribute *attr, char *buf); typedef ssize_t __device_show_handler_const(struct device *dev, const struct device_attribute *attr, -- cgit v1.2.3 From 10dde2bd66889f82bb37c16fe441f0ebb1c09c24 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 14 Sep 2026 16:30:31 +0200 Subject: module: pull out add_taint_module() to be public Other kernel code might want to call add_taint_module() so pull it out and make it global. If modules are not enabled, this defaults to a call to add_taint(), so all is fine. Reviewed-by: Johan Hovold Tested-by: Johan Hovold Reviewed-by: Bradley Morgan Reviewed-by: Petr Pavlu Acked-by: Danilo Krummrich Link: https://patch.msgid.link/20260914-bind_taint-v4-1-eadf8a090903@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- include/linux/module.h | 10 ++++++++++ kernel/module/main.c | 16 +++++++++++++--- 2 files changed, 23 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/module.h b/include/linux/module.h index 96cc98568eea..f6f90cd88f15 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -29,6 +29,7 @@ #include #include #include +#include #include #include @@ -770,6 +771,9 @@ static inline bool is_livepatch_module(struct module *mod) void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data); +void add_taint_module(struct module *mod, unsigned flag, + enum lockdep_ok lockdep_ok); + #else /* !CONFIG_MODULES... */ static inline struct module *__module_address(unsigned long addr) @@ -877,6 +881,12 @@ static inline bool module_is_coming(struct module *mod) static inline void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data) { } + +static inline void add_taint_module(struct module *mod, unsigned flag, + enum lockdep_ok lockdep_ok) +{ + add_taint(flag, lockdep_ok); +} #endif /* CONFIG_MODULES */ #ifdef CONFIG_SYSFS diff --git a/kernel/module/main.c b/kernel/module/main.c index d0e1e0bd2ad0..444d990c9983 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -191,11 +191,21 @@ static inline int strong_try_module_get(struct module *mod) return -ENOENT; } -static inline void add_taint_module(struct module *mod, unsigned flag, - enum lockdep_ok lockdep_ok) +/** + * add_taint_module: add a taint flag if not already set for a specific module + * @mod: pointer to the module that caused the problem + * @flag: one of the TAINT_* constants. + * @lockdep_ok: whether lock debugging is still OK. + * + * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for + * some noteworthy-but-not-corrupting cases, it can be set to true. + */ +void add_taint_module(struct module *mod, unsigned flag, + enum lockdep_ok lockdep_ok) { add_taint(flag, lockdep_ok); - set_bit(flag, &mod->taints); + if (mod) + set_bit(flag, &mod->taints); } /* -- cgit v1.2.3 From fcbfaffee51a452cc8efcbaa3b88ec4595678424 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 14 Sep 2026 16:30:33 +0200 Subject: driver core: add TAINT_FORCED_BIND for when userspace manually messes with devices and drivers The ability to add and remove devices from a driver through the sysfs "bind" and "unbind" files was created all those decades ago as a way that kernel developers can iterate faster, and provide a debugging way for users to attempt to add a new device to a driver without having to rebuild their kernel. This api over the years has been abused and recently come under a major fuzzing "attack" through tools like syzbot which decided that it would attempt to just randomly bind any driver to any type of device, causing loads of unneeded errors and pointless kernel patches to be generated by unsuspecting new developers. Handle all of this by adding a new taint flag, TAINT_FORCED_BIND, which will be set on the driver if the bind/unbind sysfs files are ever written to. This lets kernel developers "know" that a user is attempting to do something that is not normal, and as such, if the kernel breaks they get to keep the shiny pieces laying around on the floor. The flag is 'Y' which was unused, and can remembered as the user is "yeeting" the device being operated on here (thrown with force without regard for the thing being thrown). Note, the taint flag gets set _BEFORE_ the bind/unbind callback happens, as many times crashes/oops/warnings/failures happen within the callback, and the taint flag needs to be there to show what was being attempted. If it were to be set after the callback happens, the oops report would not properly reflect what foolishness was being attempted. Fuzzing tools like syzbot, that doesn't have hand-crafted rules to keep the tool from hitting bind/unbind, should be run with panic_on_taint enabled so that they fall over and don't continue on, thinking that they actually found a real issue. Userspace operations that rely on the bind/unbind files to work around the lack of will to upgrade a kernel image to a newer version with proper support for new devices, or the lack of will to submit valid device ids to driver authors, will still work properly, but now the kernel will be flagged in a way that will show that perhaps those users should reconsider their behavior and work to have the drivers properly support these devices in a "native" manner. Finally, the bind/unbind files can find real use-after-free issues with some drivers by forcing the process to happen virtually without having to rely on manual removal processes. Those real bugs should still be worked on, but by adding this taint flag, developers can more easily determine bug reports that are actually worth looking at. Reviewed-by: Johan Hovold Tested-by: Johan Hovold Reviewed-by: Aaron Tomlin Reviewed-by: Bradley Morgan Acked-by: Danilo Krummrich Link: https://patch.msgid.link/20260914-bind_taint-v4-3-eadf8a090903@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- Documentation/admin-guide/tainted-kernels.rst | 52 ++++++++++++++------------- drivers/base/bus.c | 3 ++ include/linux/panic.h | 3 +- include/trace/events/module.h | 3 +- kernel/panic.c | 5 +-- tools/debugging/kernel-chktaint | 8 +++++ 6 files changed, 46 insertions(+), 28 deletions(-) (limited to 'include/linux') diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst index 9ead927a37c0..abbf5e3dd749 100644 --- a/Documentation/admin-guide/tainted-kernels.rst +++ b/Documentation/admin-guide/tainted-kernels.rst @@ -79,30 +79,31 @@ which bits are set:: Table for decoding tainted state ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -=== === ====== ======================================================== -Bit Log Number Reason that got the kernel tainted -=== === ====== ======================================================== - 0 G/P 1 proprietary module was loaded - 1 _/F 2 module was force loaded - 2 _/S 4 kernel running on an out of specification system - 3 _/R 8 module was force unloaded - 4 _/M 16 processor reported a Machine Check Exception (MCE) - 5 _/B 32 bad page referenced or some unexpected page flags - 6 _/U 64 taint requested by userspace application - 7 _/D 128 kernel died recently, i.e. there was an OOPS or BUG - 8 _/A 256 ACPI table overridden by user - 9 _/W 512 kernel issued warning - 10 _/C 1024 staging driver was loaded - 11 _/I 2048 workaround for bug in platform firmware applied - 12 _/O 4096 externally-built ("out-of-tree") module was loaded - 13 _/E 8192 unsigned module was loaded - 14 _/L 16384 soft lockup occurred - 15 _/K 32768 kernel has been live patched - 16 _/X 65536 auxiliary taint, defined for and used by distros - 17 _/T 131072 kernel was built with the struct randomization plugin - 18 _/N 262144 an in-kernel test has been run - 19 _/J 524288 userspace used a mutating debug operation in fwctl -=== === ====== ======================================================== +=== === ======= ======================================================== +Bit Log Number Reason that got the kernel tainted +=== === ======= ======================================================== + 0 G/P 1 proprietary module was loaded + 1 _/F 2 module was force loaded + 2 _/S 4 kernel running on an out of specification system + 3 _/R 8 module was force unloaded + 4 _/M 16 processor reported a Machine Check Exception (MCE) + 5 _/B 32 bad page referenced or some unexpected page flags + 6 _/U 64 taint requested by userspace application + 7 _/D 128 kernel died recently, i.e. there was an OOPS or BUG + 8 _/A 256 ACPI table overridden by user + 9 _/W 512 kernel issued warning + 10 _/C 1024 staging driver was loaded + 11 _/I 2048 workaround for bug in platform firmware applied + 12 _/O 4096 externally-built ("out-of-tree") module was loaded + 13 _/E 8192 unsigned module was loaded + 14 _/L 16384 soft lockup occurred + 15 _/K 32768 kernel has been live patched + 16 _/X 65536 auxiliary taint, defined for and used by distros + 17 _/T 131072 kernel was built with the struct randomization plugin + 18 _/N 262144 an in-kernel test has been run + 19 _/J 524288 userspace used a mutating debug operation in fwctl + 20 _/Y 1048576 device was manually bound or unbound from a driver +=== === ======= ======================================================== Note: The character ``_`` is representing a blank in this table to make reading easier. @@ -189,3 +190,6 @@ More detailed explanation for tainting 19) ``J`` if userspace opened /dev/fwctl/* and performed a FWTCL_RPC_DEBUG_WRITE to use the devices debugging features. Device debugging features could cause the device to malfunction in undefined ways. + + 20) ``Y`` If userspace wrote to the `bind` or `unbind` sysfs files and + successfully bound or removed a device from a driver. diff --git a/drivers/base/bus.c b/drivers/base/bus.c index d17bd91490ee..c51ad96d4de4 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "base.h" #include "power/power.h" @@ -241,6 +242,7 @@ static ssize_t unbind_store(struct device_driver *drv, const char *buf, dev = bus_find_device_by_name(bus, NULL, buf); if (dev && dev->driver == drv) { + add_taint_module(drv->owner, TAINT_FORCED_BIND, LOCKDEP_STILL_OK); device_driver_detach(dev); err = count; } @@ -264,6 +266,7 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, dev = bus_find_device_by_name(bus, NULL, buf); if (dev && driver_match_device(drv, dev)) { + add_taint_module(drv->owner, TAINT_FORCED_BIND, LOCKDEP_STILL_OK); err = device_driver_attach(drv, dev); if (!err) { /* success */ diff --git a/include/linux/panic.h b/include/linux/panic.h index f1dd417e54b2..8e7250b0e913 100644 --- a/include/linux/panic.h +++ b/include/linux/panic.h @@ -88,7 +88,8 @@ static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) #define TAINT_RANDSTRUCT 17 #define TAINT_TEST 18 #define TAINT_FWCTL 19 -#define TAINT_FLAGS_COUNT 20 +#define TAINT_FORCED_BIND 20 +#define TAINT_FLAGS_COUNT 21 #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) struct taint_flag { diff --git a/include/trace/events/module.h b/include/trace/events/module.h index e5a006be9dc6..19df3e39bba4 100644 --- a/include/trace/events/module.h +++ b/include/trace/events/module.h @@ -26,7 +26,8 @@ struct module; { (1UL << TAINT_OOT_MODULE), "O" }, \ { (1UL << TAINT_FORCED_MODULE), "F" }, \ { (1UL << TAINT_CRAP), "C" }, \ - { (1UL << TAINT_UNSIGNED_MODULE), "E" }) + { (1UL << TAINT_UNSIGNED_MODULE), "E" }, \ + { (1UL << TAINT_FORCED_BIND), "Y" }) TRACE_EVENT(module_load, diff --git a/kernel/panic.c b/kernel/panic.c index 892045d8409e..a4dbb6b8cd2b 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -826,6 +826,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { TAINT_FLAG(RANDSTRUCT, 'T', ' '), TAINT_FLAG(TEST, 'N', ' '), TAINT_FLAG(FWCTL, 'J', ' '), + TAINT_FLAG(FORCED_BIND, 'Y', ' '), }; #undef TAINT_FLAG @@ -862,9 +863,9 @@ static void print_tainted_seq(struct seq_buf *s, bool verbose) * exact size is allocated dynamically; the initial buffer remains * as a fallback if allocation fails. * - * The verbose taint string currently requires up to 327 characters. + * The verbose taint string currently requires up to 344 characters. */ -#define INIT_TAINT_BUF_MAX 350 +#define INIT_TAINT_BUF_MAX 370 static char init_taint_buf[INIT_TAINT_BUF_MAX] __initdata; static char *taint_buf __refdata = init_taint_buf; diff --git a/tools/debugging/kernel-chktaint b/tools/debugging/kernel-chktaint index e1571c04afb5..d8628be37214 100755 --- a/tools/debugging/kernel-chktaint +++ b/tools/debugging/kernel-chktaint @@ -211,6 +211,14 @@ else addout "J" echo " * fwctl's mutating debug interface was used (#19)" fi + +T=`expr $T / 2` +if [ `expr $T % 2` -eq 0 ]; then + addout " " +else + addout "Y" + echo " * device was manually bound or unbound from a driver (#20)" +fi echo "Raw taint value as int/string: $taint/'$out'" # report on any tainted loadable modules -- cgit v1.2.3