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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 18:50:12 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 18:50:12 +0000 |
commit | 8665bd53f2f2e27e5511d90428cb3f60e6d0ce15 (patch) | |
tree | 8d58900dc0ebd4a3011f92c128d2fe45bc7c4bf2 /fs/exec.c | |
parent | Adding debian version 6.7.12-1. (diff) | |
download | linux-8665bd53f2f2e27e5511d90428cb3f60e6d0ce15.tar.xz linux-8665bd53f2f2e27e5511d90428cb3f60e6d0ce15.zip |
Merging upstream version 6.8.9.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/exec.c')
-rw-r--r-- | fs/exec.c | 108 |
1 files changed, 63 insertions, 45 deletions
@@ -66,6 +66,7 @@ #include <linux/coredump.h> #include <linux/time_namespace.h> #include <linux/user_events.h> +#include <linux/rseq.h> #include <linux/uaccess.h> #include <asm/mmu_context.h> @@ -127,7 +128,7 @@ SYSCALL_DEFINE1(uselib, const char __user *, library) struct filename *tmp = getname(library); int error = PTR_ERR(tmp); static const struct open_flags uselib_flags = { - .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, + .open_flag = O_LARGEFILE | O_RDONLY, .acc_mode = MAY_READ | MAY_EXEC, .intent = LOOKUP_OPEN, .lookup_flags = LOOKUP_FOLLOW, @@ -904,6 +905,10 @@ EXPORT_SYMBOL(transfer_args_to_stack); #endif /* CONFIG_MMU */ +/* + * On success, caller must call do_close_execat() on the returned + * struct file to close it. + */ static struct file *do_open_execat(int fd, struct filename *name, int flags) { struct file *file; @@ -948,6 +953,17 @@ exit: return ERR_PTR(err); } +/** + * open_exec - Open a path name for execution + * + * @name: path name to open with the intent of executing it. + * + * Returns ERR_PTR on failure or allocated struct file on success. + * + * As this is a wrapper for the internal do_open_execat(), callers + * must call allow_write_access() before fput() on release. Also see + * do_close_execat(). + */ struct file *open_exec(const char *name) { struct filename *filename = getname_kernel(name); @@ -1487,6 +1503,15 @@ static int prepare_bprm_creds(struct linux_binprm *bprm) return -ENOMEM; } +/* Matches do_open_execat() */ +static void do_close_execat(struct file *file) +{ + if (!file) + return; + allow_write_access(file); + fput(file); +} + static void free_bprm(struct linux_binprm *bprm) { if (bprm->mm) { @@ -1498,10 +1523,7 @@ static void free_bprm(struct linux_binprm *bprm) mutex_unlock(¤t->signal->cred_guard_mutex); abort_creds(bprm->cred); } - if (bprm->file) { - allow_write_access(bprm->file); - fput(bprm->file); - } + do_close_execat(bprm->file); if (bprm->executable) fput(bprm->executable); /* If a binfmt changed the interp, free it. */ @@ -1511,12 +1533,23 @@ static void free_bprm(struct linux_binprm *bprm) kfree(bprm); } -static struct linux_binprm *alloc_bprm(int fd, struct filename *filename) +static struct linux_binprm *alloc_bprm(int fd, struct filename *filename, int flags) { - struct linux_binprm *bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); + struct linux_binprm *bprm; + struct file *file; int retval = -ENOMEM; - if (!bprm) - goto out; + + file = do_open_execat(fd, filename, flags); + if (IS_ERR(file)) + return ERR_CAST(file); + + bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); + if (!bprm) { + do_close_execat(file); + return ERR_PTR(-ENOMEM); + } + + bprm->file = file; if (fd == AT_FDCWD || filename->name[0] == '/') { bprm->filename = filename->name; @@ -1529,18 +1562,28 @@ static struct linux_binprm *alloc_bprm(int fd, struct filename *filename) if (!bprm->fdpath) goto out_free; + /* + * Record that a name derived from an O_CLOEXEC fd will be + * inaccessible after exec. This allows the code in exec to + * choose to fail when the executable is not mmaped into the + * interpreter and an open file descriptor is not passed to + * the interpreter. This makes for a better user experience + * than having the interpreter start and then immediately fail + * when it finds the executable is inaccessible. + */ + if (get_close_on_exec(fd)) + bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE; + bprm->filename = bprm->fdpath; } bprm->interp = bprm->filename; retval = bprm_mm_init(bprm); - if (retval) - goto out_free; - return bprm; + if (!retval) + return bprm; out_free: free_bprm(bprm); -out: return ERR_PTR(retval); } @@ -1582,16 +1625,16 @@ static void check_unsafe_exec(struct linux_binprm *bprm) * will be able to manipulate the current directory, etc. * It would be nice to force an unshare instead... */ - t = p; n_fs = 1; spin_lock(&p->fs->lock); rcu_read_lock(); - while_each_thread(p, t) { + for_other_threads(p, t) { if (t->fs == p->fs) n_fs++; } rcu_read_unlock(); + /* "users" and "in_exec" locked for copy_fs() */ if (p->fs->users > n_fs) bprm->unsafe |= LSM_UNSAFE_SHARE; else @@ -1808,13 +1851,8 @@ static int exec_binprm(struct linux_binprm *bprm) return 0; } -/* - * sys_execve() executes a new program. - */ -static int bprm_execve(struct linux_binprm *bprm, - int fd, struct filename *filename, int flags) +static int bprm_execve(struct linux_binprm *bprm) { - struct file *file; int retval; retval = prepare_bprm_creds(bprm); @@ -1830,26 +1868,8 @@ static int bprm_execve(struct linux_binprm *bprm, current->in_execve = 1; sched_mm_cid_before_execve(current); - file = do_open_execat(fd, filename, flags); - retval = PTR_ERR(file); - if (IS_ERR(file)) - goto out_unmark; - sched_exec(); - bprm->file = file; - /* - * Record that a name derived from an O_CLOEXEC fd will be - * inaccessible after exec. This allows the code in exec to - * choose to fail when the executable is not mmaped into the - * interpreter and an open file descriptor is not passed to - * the interpreter. This makes for a better user experience - * than having the interpreter start and then immediately fail - * when it finds the executable is inaccessible. - */ - if (bprm->fdpath && get_close_on_exec(fd)) - bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE; - /* Set the unchanging part of bprm->cred */ retval = security_bprm_creds_for_exec(bprm); if (retval) @@ -1879,7 +1899,6 @@ out: if (bprm->point_of_no_return && !fatal_signal_pending(current)) force_fatal_sig(SIGSEGV); -out_unmark: sched_mm_cid_after_execve(current); current->fs->in_exec = 0; current->in_execve = 0; @@ -1914,7 +1933,7 @@ static int do_execveat_common(int fd, struct filename *filename, * further execve() calls fail. */ current->flags &= ~PF_NPROC_EXCEEDED; - bprm = alloc_bprm(fd, filename); + bprm = alloc_bprm(fd, filename, flags); if (IS_ERR(bprm)) { retval = PTR_ERR(bprm); goto out_ret; @@ -1963,7 +1982,7 @@ static int do_execveat_common(int fd, struct filename *filename, bprm->argc = 1; } - retval = bprm_execve(bprm, fd, filename, flags); + retval = bprm_execve(bprm); out_free: free_bprm(bprm); @@ -1988,7 +2007,7 @@ int kernel_execve(const char *kernel_filename, if (IS_ERR(filename)) return PTR_ERR(filename); - bprm = alloc_bprm(fd, filename); + bprm = alloc_bprm(fd, filename, 0); if (IS_ERR(bprm)) { retval = PTR_ERR(bprm); goto out_ret; @@ -2023,7 +2042,7 @@ int kernel_execve(const char *kernel_filename, if (retval < 0) goto out_free; - retval = bprm_execve(bprm, fd, filename, 0); + retval = bprm_execve(bprm); out_free: free_bprm(bprm); out_ret: @@ -2169,7 +2188,6 @@ static struct ctl_table fs_exec_sysctls[] = { .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_TWO, }, - { } }; static int __init init_fs_exec_sysctls(void) |