From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH 5/6] readdir.c: get compat_filldir() more or less in sync with filldir()
Date: Fri, 29 May 2020 00:49:18 +0100 [thread overview]
Message-ID: <20200528234919.4104604-2-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200528234919.4104604-1-viro@ZenIV.linux.org.uk>
From: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/readdir.c | 51 +++++++++++++++++++++++++++------------------------
1 file changed, 27 insertions(+), 24 deletions(-)
diff --git a/fs/readdir.c b/fs/readdir.c
index a9085016a619..9534675880ce 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -473,7 +473,7 @@ struct compat_linux_dirent {
struct compat_getdents_callback {
struct dir_context ctx;
struct compat_linux_dirent __user *current_dir;
- struct compat_linux_dirent __user *previous;
+ int prev_reclen;
int count;
int error;
};
@@ -481,13 +481,17 @@ struct compat_getdents_callback {
static int compat_filldir(struct dir_context *ctx, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
- struct compat_linux_dirent __user * dirent;
+ struct compat_linux_dirent __user *dirent, *prev;
struct compat_getdents_callback *buf =
container_of(ctx, struct compat_getdents_callback, ctx);
compat_ulong_t d_ino;
int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +
namlen + 2, sizeof(compat_long_t));
+ int prev_reclen;
+ buf->error = verify_dirent_name(name, namlen);
+ if (unlikely(buf->error))
+ return buf->error;
buf->error = -EINVAL; /* only used if we fail.. */
if (reclen > buf->count)
return -EINVAL;
@@ -496,29 +500,27 @@ static int compat_filldir(struct dir_context *ctx, const char *name, int namlen,
buf->error = -EOVERFLOW;
return -EOVERFLOW;
}
- dirent = buf->previous;
- if (dirent) {
- if (signal_pending(current))
- return -EINTR;
- if (__put_user(offset, &dirent->d_off))
- goto efault;
- }
+ prev_reclen = buf->prev_reclen;
+ if (prev_reclen && signal_pending(current))
+ return -EINTR;
dirent = buf->current_dir;
- if (__put_user(d_ino, &dirent->d_ino))
- goto efault;
- if (__put_user(reclen, &dirent->d_reclen))
- goto efault;
- if (copy_to_user(dirent->d_name, name, namlen))
- goto efault;
- if (__put_user(0, dirent->d_name + namlen))
- goto efault;
- if (__put_user(d_type, (char __user *) dirent + reclen - 1))
+ prev = (void __user *) dirent - prev_reclen;
+ if (!user_write_access_begin(prev, reclen + prev_reclen))
goto efault;
- buf->previous = dirent;
- dirent = (void __user *)dirent + reclen;
- buf->current_dir = dirent;
+
+ unsafe_put_user(offset, &prev->d_off, efault_end);
+ unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
+ unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
+ unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);
+ unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
+ user_write_access_end();
+
+ buf->prev_reclen = reclen;
+ buf->current_dir = (void __user *)dirent + reclen;
buf->count -= reclen;
return 0;
+efault_end:
+ user_write_access_end();
efault:
buf->error = -EFAULT;
return -EFAULT;
@@ -528,7 +530,6 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
struct compat_linux_dirent __user *, dirent, unsigned int, count)
{
struct fd f;
- struct compat_linux_dirent __user * lastdirent;
struct compat_getdents_callback buf = {
.ctx.actor = compat_filldir,
.current_dir = dirent,
@@ -546,8 +547,10 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
error = iterate_dir(f.file, &buf.ctx);
if (error >= 0)
error = buf.error;
- lastdirent = buf.previous;
- if (lastdirent) {
+ if (buf.prev_reclen) {
+ struct compat_linux_dirent __user * lastdirent;
+ lastdirent = (void __user *)buf.current_dir - buf.prev_reclen;
+
if (put_user(buf.ctx.pos, &lastdirent->d_off))
error = -EFAULT;
else
--
2.11.0
next prev parent reply other threads:[~2020-05-28 23:49 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-28 23:40 [PATCHES] uaccess base Al Viro
2020-05-28 23:48 ` [PATCHES] uaccess readdir Al Viro
2020-05-28 23:49 ` [PATCH 4/6] switch readdir(2) to unsafe_copy_dirent_name() Al Viro
2020-05-28 23:49 ` Al Viro [this message]
2020-05-28 23:49 ` [PATCH 6/6] readdir.c: get rid of the last __put_user(), drop now-useless access_ok() Al Viro
2020-05-28 23:49 ` [PATCH 1/6] uaccess: Add user_read_access_begin/end and user_write_access_begin/end Al Viro
2020-05-28 23:49 ` [PATCH 2/6] uaccess: Selectively open read or write user access Al Viro
2020-05-28 23:49 ` [PATCH 3/6] drm/i915/gem: Replace user_access_begin by user_write_access_begin Al Viro
2020-05-28 23:57 ` [PATCHES] uaccess __copy_from_user() Al Viro
2020-05-28 23:58 ` [PATCH 1/2] firewire: switch ioctl_queue_iso to use of copy_from_user() Al Viro
2020-05-28 23:58 ` [PATCH 2/2] pstore: switch to copy_from_user() Al Viro
2020-05-29 0:03 ` [PATCHES] uaccess __copy_to_user() Al Viro
2020-05-29 0:04 ` [PATCH 1/2] esas2r: don't bother with __copy_to_user() Al Viro
2020-05-29 0:04 ` [PATCH 2/2] dlmfs: convert dlmfs_file_read() to copy_to_user() Al Viro
2020-05-29 1:27 ` Linus Torvalds
2020-05-29 1:47 ` Al Viro
2020-05-29 1:54 ` Linus Torvalds
2020-05-29 3:10 ` Al Viro
2020-05-29 3:42 ` Linus Torvalds
2020-05-29 20:46 ` Al Viro
2020-05-29 20:57 ` Linus Torvalds
2020-05-29 21:06 ` Al Viro
2020-05-29 0:09 ` [PATCHES] uaccess __put_user() Al Viro
2020-05-29 0:10 ` [PATCH 1/3] compat sysinfo(2): don't bother with field-by-field copyout Al Viro
2020-05-29 0:10 ` [PATCH 2/3] scsi_ioctl.c: switch SCSI_IOCTL_GET_IDLUN to copy_to_user() Al Viro
2020-05-29 0:10 ` [PATCH 3/3] pcm_native: result of put_user() needs to be checked Al Viro
2020-05-29 0:34 ` [PATCHES] uaccess comedi compat Al Viro
2020-05-29 0:35 ` [PATCH 01/10] comedi: move compat ioctl handling to native fops Al Viro
2020-05-29 0:35 ` [PATCH 02/10] comedi: get rid of indirection via translated_ioctl() Al Viro
2020-05-29 10:34 ` Ian Abbott
2020-05-29 0:35 ` [PATCH 03/10] comedi: get rid of compat_alloc_user_space() mess in COMEDI_CHANINFO compat Al Viro
2020-05-29 10:35 ` Ian Abbott
2020-05-29 0:35 ` [PATCH 04/10] comedi: get rid of compat_alloc_user_space() mess in COMEDI_RANGEINFO compat Al Viro
2020-05-29 10:35 ` Ian Abbott
2020-05-29 0:35 ` [PATCH 05/10] comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSN compat Al Viro
2020-05-29 10:05 ` Ian Abbott
2020-05-29 0:35 ` [PATCH 06/10] comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSNLIST compat Al Viro
2020-05-29 10:36 ` Ian Abbott
2020-05-29 0:35 ` [PATCH 07/10] comedi: lift copy_from_user() into callers of __comedi_get_user_cmd() Al Viro
2020-05-29 10:37 ` Ian Abbott
2020-05-29 0:35 ` [PATCH 08/10] comedi: do_cmdtest_ioctl(): lift copyin/copyout into the caller Al Viro
2020-05-29 10:37 ` Ian Abbott
2020-05-29 0:35 ` [PATCH 09/10] comedi: do_cmd_ioctl(): " Al Viro
2020-05-29 10:38 ` Ian Abbott
2020-05-29 10:34 ` [PATCH 01/10] comedi: move compat ioctl handling to native fops Ian Abbott
2020-05-29 10:48 ` [PATCHES] uaccess comedi compat Ian Abbott
2020-05-29 14:15 ` Al Viro
2020-05-29 0:40 ` [PATCHES] uaccess i915 Al Viro
2020-05-29 5:06 ` Jani Nikula
2020-05-29 14:17 ` Al Viro
2020-05-29 0:41 ` [PATCH 1/5] i915: switch query_{topology,engine}_info() to copy_to_user() Al Viro
2020-05-29 0:41 ` [PATCH 2/5] i915: switch copy_perf_config_registers_or_number() to unsafe_put_user() Al Viro
2020-05-29 0:41 ` [PATCH 3/5] i915 compat ioctl(): just use drm_ioctl_kernel() Al Viro
2020-05-29 0:41 ` [PATCH 4/5] i915: alloc_oa_regs(): get rid of pointless access_ok() Al Viro
2020-05-29 0:41 ` [PATCH 5/5] i915:get_engines(): " Al Viro
2020-05-29 23:26 ` [PATCHES] uaccess misc Al Viro
2020-05-29 23:54 ` Linus Torvalds
2020-05-29 23:57 ` Linus Torvalds
2020-05-29 23:27 ` [PATCH 1/9] pselect6() and friends: take handling the combined 6th/7th args into helper Al Viro
2020-05-29 23:27 ` [PATCH 2/9] binfmt_elf: don't bother with __{put,copy_to}_user() Al Viro
2020-05-29 23:27 ` [PATCH 3/9] binfmt_elf_fdpic: don't use __... uaccess primitives Al Viro
2020-05-29 23:27 ` [PATCH 4/9] binfmt_flat: don't use __put_user() Al Viro
2020-05-29 23:27 ` [PATCH 5/9] x86: switch cp_stat64() to unsafe_put_user() Al Viro
2020-05-29 23:27 ` [PATCH 6/9] TEST_ACCESS_OK _never_ had been checked anywhere Al Viro
2020-05-29 23:27 ` [PATCH 7/9] user_regset_copyout_zero(): use clear_user() Al Viro
2020-05-29 23:27 ` [PATCH 8/9] x86: kvm_hv_set_msr(): use __put_user() instead of 32bit __clear_user() Al Viro
2020-05-29 23:52 ` Linus Torvalds
2020-05-30 14:31 ` Al Viro
2020-05-30 14:52 ` Al Viro
2020-05-30 16:20 ` Paolo Bonzini
2020-05-30 17:57 ` Linus Torvalds
2020-05-30 18:38 ` Al Viro
2020-05-30 18:52 ` Linus Torvalds
2020-05-30 19:14 ` Al Viro
2020-05-30 19:20 ` Linus Torvalds
2020-05-30 19:42 ` Al Viro
2020-05-30 20:43 ` Al Viro
2020-05-30 19:19 ` Al Viro
2020-05-30 19:27 ` Al Viro
2020-05-29 23:28 ` [PATCH 9/9] bpf: make bpf_check_uarg_tail_zero() use check_zeroed_user() Al Viro
2020-05-31 16:35 ` Alexei Starovoitov
2020-05-29 23:39 ` [PATCHES] uaccess hpsa Al Viro
2020-05-29 23:40 ` [PATCH 1/4] hpsa passthrough: lift {BIG_,}IOCTL_Command_struct copy{in,out} into hpsa_ioctl() Al Viro
2020-05-29 23:40 ` [PATCH 2/4] hpsa: don't bother with vmalloc for BIG_IOCTL_Command_struct Al Viro
2020-05-29 23:40 ` [PATCH 3/4] hpsa: get rid of compat_alloc_user_space() Al Viro
2020-05-29 23:40 ` [PATCH 4/4] hpsa_ioctl(): tidy up a bit Al Viro
2020-06-03 1:57 ` [PATCHES] uaccess hpsa Martin K. Petersen
2020-06-03 18:37 ` Don.Brace
2020-06-03 19:17 ` Al Viro
2020-06-03 20:53 ` Martin K. Petersen
2020-06-03 20:54 ` Al Viro
2020-06-04 14:18 ` Martin K. Petersen
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