The patch titled
Subject: proc: fix PAGE_SIZE limit of /proc/$PID/cmdline
has been added to the -mm tree. Its filename is
proc-fix-page_size-limit-of-proc-pid-cmdline.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/proc-fix-page_size-limit-of-proc-pid-cmdline.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/proc-fix-page_size-limit-of-proc-pid-cmdline.patch
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------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: proc: fix PAGE_SIZE limit of /proc/$PID/cmdline
Convert /proc/$PID/cmdline to seq_file interface.
XXX
This one must be buggy.
seq_file buffer is adjustable, so userspace can execute itself
with huge command line (which can be arbitrarily long now), then read 1 byte.
Voila, whole command line now is in kmalloced/vmalloced memory.
Imposing limit is trivial but equally lame to current PAGE_SIZE limit.
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/base.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff -puN fs/proc/base.c~proc-fix-page_size-limit-of-proc-pid-cmdline fs/proc/base.c
--- a/fs/proc/base.c~proc-fix-page_size-limit-of-proc-pid-cmdline
+++ a/fs/proc/base.c
@@ -200,9 +200,17 @@ static int proc_root_link(struct dentry
return result;
}
-static int proc_pid_cmdline(struct task_struct *task, char *buffer)
+static int proc_pid_cmdline(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
{
- return get_cmdline(task, buffer, PAGE_SIZE);
+ /*
+ * Rely on struct seq_operations::show() being called once
+ * per internal buffer allocation. See single_open(), traverse().
+ *
+ * Rely on internal buffer autoexpansion if it was entirely filled.
+ */
+ m->count += get_cmdline(task, m->buf, m->size);
+ return 0;
}
static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns,
@@ -2567,7 +2575,7 @@ static const struct pid_entry tgid_base_
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
ONE("syscall", S_IRUSR, proc_pid_syscall),
#endif
- INF("cmdline", S_IRUGO, proc_pid_cmdline),
+ ONE("cmdline", S_IRUGO, proc_pid_cmdline),
ONE("stat", S_IRUGO, proc_tgid_stat),
ONE("statm", S_IRUGO, proc_pid_statm),
REG("maps", S_IRUGO, proc_pid_maps_operations),
@@ -2903,7 +2911,7 @@ static const struct pid_entry tid_base_s
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
ONE("syscall", S_IRUSR, proc_pid_syscall),
#endif
- INF("cmdline", S_IRUGO, proc_pid_cmdline),
+ ONE("cmdline", S_IRUGO, proc_pid_cmdline),
ONE("stat", S_IRUGO, proc_tid_stat),
ONE("statm", S_IRUGO, proc_pid_statm),
REG("maps", S_IRUGO, proc_tid_maps_operations),
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
lib-test-kstrtoxc-use-array_size-instead-of-sizeof-sizeof.patch
proc-add-and-remove-proc-entry-create-checks.patch
proc-faster-proc-pid-lookup.patch
proc-make-proc_subdir_lock-static.patch
proc-remove-proc_tty_ldisc-variable.patch
proc-remove-proc_tty_ldisc-variable-fix.patch
proc-more-const-char-pointers.patch
proc-convert-proc-pid-auxv-to-seq_file-interface.patch
proc-convert-proc-pid-limits-to-seq_file-interface.patch
proc-convert-proc-pid-syscall-to-seq_file-interface.patch
proc-fix-page_size-limit-of-proc-pid-cmdline.patch
proc-convert-proc-pid-wchan-to-seq_file-interface.patch
proc-convert-proc-pid-schedstat-to-seq_file-interface.patch
proc-convert-proc-pid-oom_score-to-seq_file-interface.patch
proc-convert-proc-pid-io-to-seq_file-interface.patch
proc-convert-proc-pid-hardwall-to-seq_file-interface.patch
proc-remove-inf-macro.patch
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