From: Xiaoming Ni <nixiaoming@xxxxxxxxxx> Subject: fs/coredump: move coredump sysctls into its own file This moves the fs/coredump.c respective sysctls to its own file. Link: https://lkml.kernel.org/r/20211129211943.640266-6-mcgrof@xxxxxxxxxx Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx> Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx> Cc: Antti Palosaari <crope@xxxxxx> Cc: Christian Brauner <christian.brauner@xxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx> Cc: Eric Biggers <ebiggers@xxxxxxxxxx> Cc: Iurii Zaikin <yzaikin@xxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Lukas Middendorf <kernel@xxxxxxxxxxx> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: "Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxx> Cc: Stephen Kitt <steve@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/coredump.c | 66 ++++++++++++++++++++++++++++++++++--- fs/exec.c | 55 ------------------------------ include/linux/coredump.h | 10 +++-- kernel/sysctl.c | 2 - 4 files changed, 67 insertions(+), 66 deletions(-) --- a/fs/coredump.c~fs-coredump-move-coredump-sysctls-into-its-own-file +++ a/fs/coredump.c @@ -41,6 +41,7 @@ #include <linux/fs.h> #include <linux/path.h> #include <linux/timekeeping.h> +#include <linux/sysctl.h> #include <linux/uaccess.h> #include <asm/mmu_context.h> @@ -52,9 +53,9 @@ #include <trace/events/sched.h> -int core_uses_pid; -unsigned int core_pipe_limit; -char core_pattern[CORENAME_MAX_SIZE] = "core"; +static int core_uses_pid; +static unsigned int core_pipe_limit; +static char core_pattern[CORENAME_MAX_SIZE] = "core"; static int core_name_size = CORENAME_MAX_SIZE; struct core_name { @@ -62,8 +63,6 @@ struct core_name { int used, size; }; -/* The maximal length of core_pattern is also specified in sysctl.c */ - static int expand_corename(struct core_name *cn, int size) { char *corename = krealloc(cn->corename, size, GFP_KERNEL); @@ -893,6 +892,63 @@ int dump_align(struct coredump_params *c } EXPORT_SYMBOL(dump_align); +#ifdef CONFIG_SYSCTL + +void validate_coredump_safety(void) +{ + if (suid_dumpable == SUID_DUMP_ROOT && + core_pattern[0] != '/' && core_pattern[0] != '|') { + pr_warn( +"Unsafe core_pattern used with fs.suid_dumpable=2.\n" +"Pipe handler or fully qualified core dump path required.\n" +"Set kernel.core_pattern before fs.suid_dumpable.\n" + ); + } +} + +static int proc_dostring_coredump(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int error = proc_dostring(table, write, buffer, lenp, ppos); + + if (!error) + validate_coredump_safety(); + return error; +} + +static struct ctl_table coredump_sysctls[] = { + { + .procname = "core_uses_pid", + .data = &core_uses_pid, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "core_pattern", + .data = core_pattern, + .maxlen = CORENAME_MAX_SIZE, + .mode = 0644, + .proc_handler = proc_dostring_coredump, + }, + { + .procname = "core_pipe_limit", + .data = &core_pipe_limit, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; + +static int __init init_fs_coredump_sysctls(void) +{ + register_sysctl_init("kernel", coredump_sysctls); + return 0; +} +fs_initcall(init_fs_coredump_sysctls); +#endif /* CONFIG_SYSCTL */ + /* * The purpose of always_dump_vma() is to make sure that special kernel mappings * that are useful for post-mortem analysis are included in every core dump. --- a/fs/exec.c~fs-coredump-move-coredump-sysctls-into-its-own-file +++ a/fs/exec.c @@ -2103,20 +2103,6 @@ COMPAT_SYSCALL_DEFINE5(execveat, int, fd #ifdef CONFIG_SYSCTL -static void validate_coredump_safety(void) -{ -#ifdef CONFIG_COREDUMP - if (suid_dumpable == SUID_DUMP_ROOT && - core_pattern[0] != '/' && core_pattern[0] != '|') { - pr_warn( -"Unsafe core_pattern used with fs.suid_dumpable=2.\n" -"Pipe handler or fully qualified core dump path required.\n" -"Set kernel.core_pattern before fs.suid_dumpable.\n" - ); - } -#endif -} - static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { @@ -2140,50 +2126,9 @@ static struct ctl_table fs_exec_sysctls[ { } }; -#ifdef CONFIG_COREDUMP - -static int proc_dostring_coredump(struct ctl_table *table, int write, - void *buffer, size_t *lenp, loff_t *ppos) -{ - int error = proc_dostring(table, write, buffer, lenp, ppos); - - if (!error) - validate_coredump_safety(); - return error; -} - -static struct ctl_table kernel_exec_sysctls[] = { - { - .procname = "core_uses_pid", - .data = &core_uses_pid, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { - .procname = "core_pattern", - .data = core_pattern, - .maxlen = CORENAME_MAX_SIZE, - .mode = 0644, - .proc_handler = proc_dostring_coredump, - }, - { - .procname = "core_pipe_limit", - .data = &core_pipe_limit, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { } -}; -#endif - static int __init init_fs_exec_sysctls(void) { register_sysctl_init("fs", fs_exec_sysctls); -#ifdef CONFIG_COREDUMP - register_sysctl_init("kernel", kernel_exec_sysctls); -#endif return 0; } --- a/include/linux/coredump.h~fs-coredump-move-coredump-sysctls-into-its-own-file +++ a/include/linux/coredump.h @@ -14,10 +14,6 @@ struct core_vma_metadata { unsigned long dump_size; }; -extern int core_uses_pid; -extern char core_pattern[]; -extern unsigned int core_pipe_limit; - /* * These are the only things you should do on a core-file: use only these * functions to write out all the necessary info. @@ -37,4 +33,10 @@ extern void do_coredump(const kernel_sig static inline void do_coredump(const kernel_siginfo_t *siginfo) {} #endif +#if defined(CONFIG_COREDUMP) && defined(CONFIG_SYSCTL) +extern void validate_coredump_safety(void); +#else +static inline void validate_coredump_safety(void) {} +#endif + #endif /* _LINUX_COREDUMP_H */ --- a/kernel/sysctl.c~fs-coredump-move-coredump-sysctls-into-its-own-file +++ a/kernel/sysctl.c @@ -62,12 +62,10 @@ #include <linux/capability.h> #include <linux/binfmts.h> #include <linux/sched/sysctl.h> -#include <linux/sched/coredump.h> #include <linux/kexec.h> #include <linux/bpf.h> #include <linux/mount.h> #include <linux/userfaultfd_k.h> -#include <linux/coredump.h> #include <linux/latencytop.h> #include <linux/pid.h> #include <linux/delayacct.h> _
