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-rw-r--r--fs/exec.c126
1 files changed, 79 insertions, 47 deletions
diff --git a/fs/exec.c b/fs/exec.c
index 5c833c18d0d..c0c636e34f6 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -46,7 +46,6 @@
#include <linux/proc_fs.h>
#include <linux/mount.h>
#include <linux/security.h>
-#include <linux/ima.h>
#include <linux/syscalls.h>
#include <linux/tsacct_kern.h>
#include <linux/cn_proc.h>
@@ -55,6 +54,7 @@
#include <linux/kmod.h>
#include <linux/fsnotify.h>
#include <linux/fs_struct.h>
+#include <linux/pipe_fs_i.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
@@ -63,6 +63,7 @@
int core_uses_pid;
char core_pattern[CORENAME_MAX_SIZE] = "core";
+unsigned int core_pipe_limit;
int suid_dumpable = 0;
/* The maximal length of core_pattern is also specified in sysctl.c */
@@ -622,10 +623,8 @@ int setup_arg_pages(struct linux_binprm *bprm,
/* Move stack pages down in memory. */
if (stack_shift) {
ret = shift_arg_pages(vma, stack_shift);
- if (ret) {
- up_write(&mm->mmap_sem);
- return ret;
- }
+ if (ret)
+ goto out_unlock;
}
#ifdef CONFIG_STACK_GROWSUP
@@ -639,7 +638,7 @@ int setup_arg_pages(struct linux_binprm *bprm,
out_unlock:
up_write(&mm->mmap_sem);
- return 0;
+ return ret;
}
EXPORT_SYMBOL(setup_arg_pages);
@@ -1209,9 +1208,6 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
retval = security_bprm_check(bprm);
if (retval)
return retval;
- retval = ima_bprm_check(bprm);
- if (retval)
- return retval;
/* kernel module loader fixup */
/* so we don't try to load run modprobe in kernel space. */
@@ -1393,18 +1389,16 @@ out_ret:
return retval;
}
-int set_binfmt(struct linux_binfmt *new)
+void set_binfmt(struct linux_binfmt *new)
{
- struct linux_binfmt *old = current->binfmt;
+ struct mm_struct *mm = current->mm;
- if (new) {
- if (!try_module_get(new->module))
- return -1;
- }
- current->binfmt = new;
- if (old)
- module_put(old->module);
- return 0;
+ if (mm->binfmt)
+ module_put(mm->binfmt->module);
+
+ mm->binfmt = new;
+ if (new)
+ __module_get(new->module);
}
EXPORT_SYMBOL(set_binfmt);
@@ -1728,6 +1722,29 @@ int get_dumpable(struct mm_struct *mm)
return (ret >= 2) ? 2 : ret;
}
+static void wait_for_dump_helpers(struct file *file)
+{
+ struct pipe_inode_info *pipe;
+
+ pipe = file->f_path.dentry->d_inode->i_pipe;
+
+ pipe_lock(pipe);
+ pipe->readers++;
+ pipe->writers--;
+
+ while ((pipe->readers > 1) && (!signal_pending(current))) {
+ wake_up_interruptible_sync(&pipe->wait);
+ kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
+ pipe_wait(pipe);
+ }
+
+ pipe->readers--;
+ pipe->writers++;
+ pipe_unlock(pipe);
+
+}
+
+
void do_coredump(long signr, int exit_code, struct pt_regs *regs)
{
struct core_state core_state;
@@ -1744,11 +1761,12 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
char **helper_argv = NULL;
int helper_argc = 0;
- char *delimit;
+ int dump_count = 0;
+ static atomic_t core_dump_count = ATOMIC_INIT(0);
audit_core_dumps(signr);
- binfmt = current->binfmt;
+ binfmt = mm->binfmt;
if (!binfmt || !binfmt->core_dump)
goto fail;
@@ -1799,54 +1817,63 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
lock_kernel();
ispipe = format_corename(corename, signr);
unlock_kernel();
- /*
- * Don't bother to check the RLIMIT_CORE value if core_pattern points
- * to a pipe. Since we're not writing directly to the filesystem
- * RLIMIT_CORE doesn't really apply, as no actual core file will be
- * created unless the pipe reader choses to write out the core file
- * at which point file size limits and permissions will be imposed
- * as it does with any other process
- */
+
if ((!ispipe) && (core_limit < binfmt->min_coredump))
goto fail_unlock;
if (ispipe) {
+ if (core_limit == 0) {
+ /*
+ * Normally core limits are irrelevant to pipes, since
+ * we're not writing to the file system, but we use
+ * core_limit of 0 here as a speacial value. Any
+ * non-zero limit gets set to RLIM_INFINITY below, but
+ * a limit of 0 skips the dump. This is a consistent
+ * way to catch recursive crashes. We can still crash
+ * if the core_pattern binary sets RLIM_CORE = !0
+ * but it runs as root, and can do lots of stupid things
+ * Note that we use task_tgid_vnr here to grab the pid
+ * of the process group leader. That way we get the
+ * right pid if a thread in a multi-threaded
+ * core_pattern process dies.
+ */
+ printk(KERN_WARNING
+ "Process %d(%s) has RLIMIT_CORE set to 0\n",
+ task_tgid_vnr(current), current->comm);
+ printk(KERN_WARNING "Aborting core\n");
+ goto fail_unlock;
+ }
+
+ dump_count = atomic_inc_return(&core_dump_count);
+ if (core_pipe_limit && (core_pipe_limit < dump_count)) {
+ printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n",
+ task_tgid_vnr(current), current->comm);
+ printk(KERN_WARNING "Skipping core dump\n");
+ goto fail_dropcount;
+ }
+
helper_argv = argv_split(GFP_KERNEL, corename+1, &helper_argc);
if (!helper_argv) {
printk(KERN_WARNING "%s failed to allocate memory\n",
__func__);
- goto fail_unlock;
- }
- /* Terminate the string before the first option */
- delimit = strchr(corename, ' ');
- if (delimit)
- *delimit = '\0';
- delimit = strrchr(helper_argv[0], '/');
- if (delimit)
- delimit++;
- else
- delimit = helper_argv[0];
- if (!strcmp(delimit, current->comm)) {
- printk(KERN_NOTICE "Recursive core dump detected, "
- "aborting\n");
- goto fail_unlock;
+ goto fail_dropcount;
}
core_limit = RLIM_INFINITY;
/* SIGPIPE can happen, but it's just never processed */
- if (call_usermodehelper_pipe(corename+1, helper_argv, NULL,
+ if (call_usermodehelper_pipe(helper_argv[0], helper_argv, NULL,
&file)) {
printk(KERN_INFO "Core dump to %s pipe failed\n",
corename);
- goto fail_unlock;
+ goto fail_dropcount;
}
} else
file = filp_open(corename,
O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
0600);
if (IS_ERR(file))
- goto fail_unlock;
+ goto fail_dropcount;
inode = file->f_path.dentry->d_inode;
if (inode->i_nlink > 1)
goto close_fail; /* multiple links - don't dump */
@@ -1875,7 +1902,12 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
if (retval)
current->signal->group_exit_code |= 0x80;
close_fail:
+ if (ispipe && core_pipe_limit)
+ wait_for_dump_helpers(file);
filp_close(file, NULL);
+fail_dropcount:
+ if (dump_count)
+ atomic_dec(&core_dump_count);
fail_unlock:
if (helper_argv)
argv_free(helper_argv);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-23 01:56:13 +0000