From 1fbbe0ccd56a59a5c07f73fe47bd60ca9a464409 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Thu, 20 Dec 2018 17:23:43 +0100 Subject: drbd: Avoid Clang warning about pointless switch statment [ Upstream commit a52c5a16cf19d8a85831bb1b915a221dd4ffae3c ] There are several warnings from Clang about no case statement matching the constant 0: In file included from drivers/block/drbd/drbd_receiver.c:48: In file included from drivers/block/drbd/drbd_int.h:48: In file included from ./include/linux/drbd_genl_api.h:54: In file included from ./include/linux/genl_magic_struct.h:236: ./include/linux/drbd_genl.h:321:1: warning: no case matching constant switch condition '0' GENL_struct(DRBD_NLA_HELPER, 24, drbd_helper_info, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/genl_magic_struct.h:220:10: note: expanded from macro 'GENL_struct' switch (0) { ^ Silence this warning by adding a 'case 0:' statement. Additionally, adjust the alignment of the statements in the ct_assert_unique macro to avoid a checkpatch warning. This solution was originally sent by Arnd Bergmann with a default case statement: https://lore.kernel.org/patchwork/patch/756723/ Link: https://github.com/ClangBuiltLinux/linux/issues/43 Suggested-by: Lars Ellenberg Signed-off-by: Nathan Chancellor Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- include/linux/genl_magic_struct.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/genl_magic_struct.h b/include/linux/genl_magic_struct.h index eecd19b37001..250e9be65e74 100644 --- a/include/linux/genl_magic_struct.h +++ b/include/linux/genl_magic_struct.h @@ -185,6 +185,7 @@ static inline void ct_assert_unique_operations(void) { switch (0) { #include GENL_MAGIC_INCLUDE_FILE + case 0: ; } } @@ -203,6 +204,7 @@ static inline void ct_assert_unique_top_level_attributes(void) { switch (0) { #include GENL_MAGIC_INCLUDE_FILE + case 0: ; } } @@ -212,7 +214,8 @@ static inline void ct_assert_unique_top_level_attributes(void) static inline void ct_assert_unique_ ## s_name ## _attributes(void) \ { \ switch (0) { \ - s_fields \ + s_fields \ + case 0: \ ; \ } \ } -- cgit v1.2.3 From a7ea4de3664593a4d79cb7e62e3c8736cabb5d3c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 9 Jan 2018 07:21:15 -0800 Subject: string: drop __must_check from strscpy() and restore strscpy() usages in cgroup MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 08a77676f9c5fc69a681ccd2cd8140e65dcb26c7 upstream. e7fd37ba1217 ("cgroup: avoid copying strings longer than the buffers") converted possibly unsafe strncpy() usages in cgroup to strscpy(). However, although the callsites are completely fine with truncated copied, because strscpy() is marked __must_check, it led to the following warnings. kernel/cgroup/cgroup.c: In function ‘cgroup_file_name’: kernel/cgroup/cgroup.c:1400:10: warning: ignoring return value of ‘strscpy’, declared with attribute warn_unused_result [-Wunused-result] strscpy(buf, cft->name, CGROUP_FILE_NAME_MAX); ^ To avoid the warnings, 50034ed49645 ("cgroup: use strlcpy() instead of strscpy() to avoid spurious warning") switched them to strlcpy(). strlcpy() is worse than strlcpy() because it unconditionally runs strlen() on the source string, and the only reason we switched to strlcpy() here was because it was lacking __must_check, which doesn't reflect any material differences between the two function. It's just that someone added __must_check to strscpy() and not to strlcpy(). These basic string copy operations are used in variety of ways, and one of not-so-uncommon use cases is safely handling truncated copies, where the caller naturally doesn't care about the return value. The __must_check doesn't match the actual use cases and forces users to opt for inferior variants which lack __must_check by happenstance or spread ugly (void) casts. Remove __must_check from strscpy() and restore strscpy() usages in cgroup. Signed-off-by: Tejun Heo Suggested-by: Linus Torvalds Cc: Ma Shimiao Cc: Arnd Bergmann Cc: Chris Metcalf [backport only the string.h portion to remove build warnings starting to show up - gregkh] Signed-off-by: Greg Kroah-Hartman --- include/linux/string.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/string.h b/include/linux/string.h index 98bb781a2eff..c026b7a19e26 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -26,7 +26,7 @@ extern char * strncpy(char *,const char *, __kernel_size_t); size_t strlcpy(char *, const char *, size_t); #endif #ifndef __HAVE_ARCH_STRSCPY -ssize_t __must_check strscpy(char *, const char *, size_t); +ssize_t strscpy(char *, const char *, size_t); #endif #ifndef __HAVE_ARCH_STRCAT extern char * strcat(char *, const char *); -- cgit v1.2.3 From b661fff5f8a0f19824df91cc3905ba2c5b54dc87 Mon Sep 17 00:00:00 2001 From: Vladis Dronov Date: Tue, 29 Jan 2019 11:58:35 +0100 Subject: HID: debug: fix the ring buffer implementation commit 13054abbaa4f1fd4e6f3b4b63439ec033b4c8035 upstream. Ring buffer implementation in hid_debug_event() and hid_debug_events_read() is strange allowing lost or corrupted data. After commit 717adfdaf147 ("HID: debug: check length before copy_to_user()") it is possible to enter an infinite loop in hid_debug_events_read() by providing 0 as count, this locks up a system. Fix this by rewriting the ring buffer implementation with kfifo and simplify the code. This fixes CVE-2019-3819. v2: fix an execution logic and add a comment v3: use __set_current_state() instead of set_current_state() Backport to v4.4: some (tree-wide) patches are missing in v4.4 so cherry-pick relevant pieces from: * 6396bb22151 ("treewide: kzalloc() -> kcalloc()") * a9a08845e9ac ("vfs: do bulk POLL* -> EPOLL* replacement") * 92529623d242 ("HID: debug: improve hid_debug_event()") * 174cd4b1e5fb ("sched/headers: Prepare to move signal wakeup & sigpending methods from into ") Link: https://bugzilla.redhat.com/show_bug.cgi?id=1669187 Cc: stable@vger.kernel.org # v4.18+ Fixes: cd667ce24796 ("HID: use debugfs for events/reports dumping") Fixes: 717adfdaf147 ("HID: debug: check length before copy_to_user()") Signed-off-by: Vladis Dronov Reviewed-by: Oleg Nesterov Signed-off-by: Benjamin Tissoires Signed-off-by: Greg Kroah-Hartman --- include/linux/hid-debug.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/hid-debug.h b/include/linux/hid-debug.h index 8663f216c563..2d6100edf204 100644 --- a/include/linux/hid-debug.h +++ b/include/linux/hid-debug.h @@ -24,7 +24,10 @@ #ifdef CONFIG_DEBUG_FS +#include + #define HID_DEBUG_BUFSIZE 512 +#define HID_DEBUG_FIFOSIZE 512 void hid_dump_input(struct hid_device *, struct hid_usage *, __s32); void hid_dump_report(struct hid_device *, int , u8 *, int); @@ -37,11 +40,8 @@ void hid_debug_init(void); void hid_debug_exit(void); void hid_debug_event(struct hid_device *, char *); - struct hid_debug_list { - char *hid_debug_buf; - int head; - int tail; + DECLARE_KFIFO_PTR(hid_debug_fifo, char); struct fasync_struct *fasync; struct hid_device *hdev; struct list_head node; @@ -64,4 +64,3 @@ struct hid_debug_list { #endif #endif - -- cgit v1.2.3