diff options
| author | Christoph Hellwig <hch@lst.de> | 2020-08-11 18:33:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-12 10:57:59 -0700 |
| commit | fe81417596fa8b6577fedb7e206ff3e4c7015c13 (patch) | |
| tree | 848274a3e2d7426773d12ed77d83a8552802f51c | |
| parent | 3d13f313ce4c34c524ccc37986fe77172f601ff3 (diff) | |
| download | memblock-fe81417596fa8b6577fedb7e206ff3e4c7015c13.tar.gz | |
exec: use force_uaccess_begin during exec and exit
Both exec and exit want to ensure that the uaccess routines actually do
access user pointers. Use the newly added force_uaccess_begin helper
instead of an open coded set_fs for that to prepare for kernel builds
where set_fs() does not exist.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/20200710135706.537715-7-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/exec.c | 7 | ||||
| -rw-r--r-- | kernel/exit.c | 2 |
2 files changed, 7 insertions, 2 deletions
diff --git a/fs/exec.c b/fs/exec.c index 3698252719a33d..29ef78ae9f5020 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1402,7 +1402,12 @@ int begin_new_exec(struct linux_binprm * bprm) if (retval) goto out_unlock; - set_fs(USER_DS); + /* + * Ensure that the uaccess routines can actually operate on userspace + * pointers: + */ + force_uaccess_begin(); + me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | PF_NOFREEZE | PF_NO_SETAFFINITY); flush_thread(); diff --git a/kernel/exit.c b/kernel/exit.c index e731c414e024a0..c2d2961576f2ab 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -732,7 +732,7 @@ void __noreturn do_exit(long code) * mm_release()->clear_child_tid() from writing to a user-controlled * kernel address. */ - set_fs(USER_DS); + force_uaccess_begin(); if (unlikely(in_atomic())) { pr_info("note: %s[%d] exited with preempt_count %d\n", |