From: David Laight <David.Laight@ACULAB.COM>
To: 'Al Viro' <viro@zeniv.linux.org.uk>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: RE: [PATCHES] uaccess simple access_ok() removals
Date: Sun, 10 May 2020 14:34:04 +0000 [thread overview]
Message-ID: <847a5160e4e64a82962dc1531cd52e11@AcuMS.aculab.com> (raw)
In-Reply-To: <20200509234124.GM23230@ZenIV.linux.org.uk>
From: Al Viro
> Sent: 10 May 2020 00:41
>
> One of the uaccess-related branches; this one is just the
> cases when access_ok() calls are trivially pointless - the address
> in question gets fed only to primitives that do access_ok() checks
> themselves.
There is also the check in rw_copy_check_uvector() that should
always be replicated by the copy_to/from_user() in _copy_to/from_iter().
And the strange call to rw_copy_check_uvector() in mm/process_vm_access.c
which carefully avoids the access_ok() check for the target process.
I did a quick look, but failed to see an obvious check further
down the call path.
The code is doing a read/write from another process, not sure when it
is used - not by gdb.
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
prev parent reply other threads:[~2020-05-10 14:34 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-09 23:41 [PATCHES] uaccess simple access_ok() removals Al Viro
2020-05-09 23:45 ` [PATCH 01/20] dlmfs_file_write(): get rid of pointless access_ok() Al Viro
2020-05-09 23:45 ` [PATCH 02/20] fat_dir_ioctl(): hadn't needed that access_ok() for more than a decade Al Viro
2020-05-09 23:45 ` [PATCH 03/20] btrfs_ioctl_send(): don't bother with access_ok() Al Viro
2020-05-09 23:45 ` [PATCH 04/20] FIEMAP: " Al Viro
2020-05-10 7:02 ` Christoph Hellwig
2020-05-13 19:02 ` Al Viro
2020-05-13 19:38 ` Christoph Hellwig
2020-05-29 15:01 ` Al Viro
2020-05-09 23:45 ` [PATCH 05/20] tomoyo_write_control(): get rid of pointless access_ok() Al Viro
2020-05-10 0:50 ` Tetsuo Handa
2020-05-10 0:57 ` Linus Torvalds
2020-05-10 1:04 ` Tetsuo Handa
2020-05-10 3:01 ` Al Viro
2020-05-09 23:45 ` [PATCH 06/20] n_hdlc_tty_read(): remove " Al Viro
2020-05-15 10:53 ` Greg Kroah-Hartman
2020-05-09 23:45 ` [PATCH 07/20] nvram: drop useless access_ok() Al Viro
2020-05-15 10:54 ` Greg Kroah-Hartman
2020-05-09 23:45 ` [PATCH 08/20] cm4000_cs.c cmm_ioctl(): get rid of pointless access_ok() Al Viro
2020-05-09 23:45 ` [PATCH 09/20] drivers/fpga/dfl-fme-pr.c: " Al Viro
2020-05-09 23:45 ` [PATCH 10/20] drivers/fpga/dfl-afu-dma-region.c: " Al Viro
2020-05-09 23:45 ` [PATCH 11/20] amifb: get rid of pointless access_ok() calls Al Viro
2020-05-14 13:45 ` Bartlomiej Zolnierkiewicz
2020-05-14 14:07 ` Al Viro
2020-05-14 14:25 ` Bartlomiej Zolnierkiewicz
2020-05-14 17:41 ` Al Viro
2020-05-14 20:21 ` Geert Uytterhoeven
2020-05-09 23:45 ` [PATCH 12/20] omapfb: " Al Viro
2020-05-14 13:39 ` Bartlomiej Zolnierkiewicz
2020-05-09 23:45 ` [PATCH 13/20] drivers/crypto/ccp/sev-dev.c: get rid of pointless access_ok() Al Viro
2020-05-09 23:45 ` [PATCH 14/20] via-pmu: don't bother with access_ok() Al Viro
2020-05-09 23:45 ` [PATCH 15/20] drm_read(): get rid of pointless access_ok() Al Viro
2020-05-09 23:45 ` [PATCH 16/20] efi_test: " Al Viro
2020-05-09 23:45 ` [PATCH 17/20] lpfc_debugfs: " Al Viro
2020-05-09 23:45 ` [PATCH 18/20] usb: get rid of pointless access_ok() calls Al Viro
2020-05-15 10:53 ` Greg Kroah-Hartman
2020-05-09 23:45 ` [PATCH 19/20] hfi1: get rid of pointless access_ok() Al Viro
2020-05-09 23:45 ` [PATCH 4/4] vmci_host: " Al Viro
2020-05-15 10:53 ` Greg Kroah-Hartman
2020-05-10 0:34 ` [PATCHES] uaccess simple access_ok() removals Linus Torvalds
2020-05-10 3:27 ` Al Viro
2020-05-10 14:34 ` David Laight [this message]
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