From 79beea2db0431536d79fc5d321225fb42f955466 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 15 Apr 2025 10:27:50 +0200 Subject: [PATCH] fs: remove uselib() system call This system call has been deprecated for quite a while now. Let's try and remove it from the kernel completely. Link: https://lore.kernel.org/20250415-kanufahren-besten-02ac00e6becd@brauner Acked-by: Kees Cook Signed-off-by: Christian Brauner --- arch/m68k/configs/amcore_defconfig | 1 - arch/x86/configs/i386_defconfig | 1 - arch/xtensa/configs/cadence_csp_defconfig | 1 - fs/binfmt_elf.c | 76 ---------------------- fs/exec.c | 60 ----------------- include/linux/binfmts.h | 1 - init/Kconfig | 10 --- tools/testing/selftests/bpf/config.aarch64 | 1 - tools/testing/selftests/bpf/config.s390x | 1 - 9 files changed, 152 deletions(-) diff --git a/arch/m68k/configs/amcore_defconfig b/arch/m68k/configs/amcore_defconfig index 67a0d157122d..71ebe444ab71 100644 --- a/arch/m68k/configs/amcore_defconfig +++ b/arch/m68k/configs/amcore_defconfig @@ -2,7 +2,6 @@ CONFIG_LOCALVERSION="amcore-002" CONFIG_DEFAULT_HOSTNAME="amcore" CONFIG_SYSVIPC=y # CONFIG_FHANDLE is not set -# CONFIG_USELIB is not set CONFIG_LOG_BUF_SHIFT=14 CONFIG_CC_OPTIMIZE_FOR_SIZE=y # CONFIG_AIO is not set diff --git a/arch/x86/configs/i386_defconfig b/arch/x86/configs/i386_defconfig index 91801138b10b..7cd2f395f301 100644 --- a/arch/x86/configs/i386_defconfig +++ b/arch/x86/configs/i386_defconfig @@ -1,7 +1,6 @@ CONFIG_WERROR=y CONFIG_SYSVIPC=y CONFIG_POSIX_MQUEUE=y -CONFIG_USELIB=y CONFIG_AUDIT=y CONFIG_NO_HZ=y CONFIG_HIGH_RES_TIMERS=y diff --git a/arch/xtensa/configs/cadence_csp_defconfig b/arch/xtensa/configs/cadence_csp_defconfig index 91c4c4cae8a7..49f50d1bd724 100644 --- a/arch/xtensa/configs/cadence_csp_defconfig +++ b/arch/xtensa/configs/cadence_csp_defconfig @@ -1,6 +1,5 @@ CONFIG_SYSVIPC=y CONFIG_POSIX_MQUEUE=y -CONFIG_USELIB=y CONFIG_NO_HZ_IDLE=y CONFIG_HIGH_RES_TIMERS=y CONFIG_IRQ_TIME_ACCOUNTING=y diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 584fa89bc877..7e2afe3220f7 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -68,12 +68,6 @@ static int load_elf_binary(struct linux_binprm *bprm); -#ifdef CONFIG_USELIB -static int load_elf_library(struct file *); -#else -#define load_elf_library NULL -#endif - /* * If we don't support core dumping, then supply a NULL so we * don't even try. @@ -101,7 +95,6 @@ static int elf_core_dump(struct coredump_params *cprm); static struct linux_binfmt elf_format = { .module = THIS_MODULE, .load_binary = load_elf_binary, - .load_shlib = load_elf_library, #ifdef CONFIG_COREDUMP .core_dump = elf_core_dump, .min_coredump = ELF_EXEC_PAGESIZE, @@ -1361,75 +1354,6 @@ out_free_ph: goto out; } -#ifdef CONFIG_USELIB -/* This is really simpleminded and specialized - we are loading an - a.out library that is given an ELF header. */ -static int load_elf_library(struct file *file) -{ - struct elf_phdr *elf_phdata; - struct elf_phdr *eppnt; - int retval, error, i, j; - struct elfhdr elf_ex; - - error = -ENOEXEC; - retval = elf_read(file, &elf_ex, sizeof(elf_ex), 0); - if (retval < 0) - goto out; - - if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) - goto out; - - /* First of all, some simple consistency checks */ - if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || - !elf_check_arch(&elf_ex) || !file->f_op->mmap) - goto out; - if (elf_check_fdpic(&elf_ex)) - goto out; - - /* Now read in all of the header information */ - - j = sizeof(struct elf_phdr) * elf_ex.e_phnum; - /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ - - error = -ENOMEM; - elf_phdata = kmalloc(j, GFP_KERNEL); - if (!elf_phdata) - goto out; - - eppnt = elf_phdata; - error = -ENOEXEC; - retval = elf_read(file, eppnt, j, elf_ex.e_phoff); - if (retval < 0) - goto out_free_ph; - - for (j = 0, i = 0; ip_type == PT_LOAD) - j++; - if (j != 1) - goto out_free_ph; - - while (eppnt->p_type != PT_LOAD) - eppnt++; - - /* Now use mmap to map the library into memory. */ - error = elf_load(file, ELF_PAGESTART(eppnt->p_vaddr), - eppnt, - PROT_READ | PROT_WRITE | PROT_EXEC, - MAP_FIXED_NOREPLACE | MAP_PRIVATE, - 0); - - if (error != ELF_PAGESTART(eppnt->p_vaddr)) - goto out_free_ph; - - error = 0; - -out_free_ph: - kfree(elf_phdata); -out: - return error; -} -#endif /* #ifdef CONFIG_USELIB */ - #ifdef CONFIG_ELF_CORE /* * ELF core dumper diff --git a/fs/exec.c b/fs/exec.c index 8e4ea5f1e64c..cfbb2b9ee3c9 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -115,66 +115,6 @@ bool path_noexec(const struct path *path) (path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC); } -#ifdef CONFIG_USELIB -/* - * Note that a shared library must be both readable and executable due to - * security reasons. - * - * Also note that we take the address to load from the file itself. - */ -SYSCALL_DEFINE1(uselib, const char __user *, library) -{ - struct linux_binfmt *fmt; - struct file *file; - struct filename *tmp = getname(library); - int error = PTR_ERR(tmp); - static const struct open_flags uselib_flags = { - .open_flag = O_LARGEFILE | O_RDONLY, - .acc_mode = MAY_READ | MAY_EXEC, - .intent = LOOKUP_OPEN, - .lookup_flags = LOOKUP_FOLLOW, - }; - - if (IS_ERR(tmp)) - goto out; - - file = do_filp_open(AT_FDCWD, tmp, &uselib_flags); - putname(tmp); - error = PTR_ERR(file); - if (IS_ERR(file)) - goto out; - - /* - * Check do_open_execat() for an explanation. - */ - error = -EACCES; - if (WARN_ON_ONCE(!S_ISREG(file_inode(file)->i_mode)) || - path_noexec(&file->f_path)) - goto exit; - - error = -ENOEXEC; - - read_lock(&binfmt_lock); - list_for_each_entry(fmt, &formats, lh) { - if (!fmt->load_shlib) - continue; - if (!try_module_get(fmt->module)) - continue; - read_unlock(&binfmt_lock); - error = fmt->load_shlib(file); - read_lock(&binfmt_lock); - put_binfmt(fmt); - if (error != -ENOEXEC) - break; - } - read_unlock(&binfmt_lock); -exit: - fput(file); -out: - return error; -} -#endif /* #ifdef CONFIG_USELIB */ - #ifdef CONFIG_MMU /* * The nascent bprm->mm is not visible until exec_mmap() but it can diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 1625c8529e70..65abd5ab8836 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -90,7 +90,6 @@ struct linux_binfmt { struct list_head lh; struct module *module; int (*load_binary)(struct linux_binprm *); - int (*load_shlib)(struct file *); #ifdef CONFIG_COREDUMP int (*core_dump)(struct coredump_params *cprm); unsigned long min_coredump; /* minimal dump size */ diff --git a/init/Kconfig b/init/Kconfig index dd2ea3b9a799..0940fbf024f0 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -479,16 +479,6 @@ config CROSS_MEMORY_ATTACH to directly read from or write to another process' address space. See the man page for more details. -config USELIB - bool "uselib syscall (for libc5 and earlier)" - default ALPHA || M68K || SPARC - help - This option enables the uselib syscall, a system call used in the - dynamic linker from libc5 and earlier. glibc does not use this - system call. If you intend to run programs built on libc5 or - earlier, you may need to enable this syscall. Current systems - running glibc can safely disable this. - config AUDIT bool "Auditing support" depends on NET diff --git a/tools/testing/selftests/bpf/config.aarch64 b/tools/testing/selftests/bpf/config.aarch64 index 3720b7611523..e1495a4bbc99 100644 --- a/tools/testing/selftests/bpf/config.aarch64 +++ b/tools/testing/selftests/bpf/config.aarch64 @@ -158,7 +158,6 @@ CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_TUN=y CONFIG_UNIX=y CONFIG_UPROBES=y -CONFIG_USELIB=y CONFIG_USER_NS=y CONFIG_VETH=y CONFIG_VLAN_8021Q=y diff --git a/tools/testing/selftests/bpf/config.s390x b/tools/testing/selftests/bpf/config.s390x index 706931a8c2c6..26c3bc2ce11d 100644 --- a/tools/testing/selftests/bpf/config.s390x +++ b/tools/testing/selftests/bpf/config.s390x @@ -128,7 +128,6 @@ CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_TUN=y CONFIG_UNIX=y CONFIG_UPROBES=y -CONFIG_USELIB=y CONFIG_USER_NS=y CONFIG_VETH=y CONFIG_VLAN_8021Q=y -- 2.25.1