Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1157383

[PATCH 3.10 45/46] vfs: read file_handle only once in handle_to_path

Show all headers | View raw

3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sasha Levin <sasha.levin@oracle.com>

commit 161f873b89136eb1e69477c847d5a5033239d9ba upstream.

We used to read file_handle twice.  Once to get the amount of extra
bytes, and once to fetch the entire structure.

This may be problematic since we do size verifications only after the
first read, so if the number of extra bytes changes in userspace between
the first and second calls, we'll have an incoherent view of
file_handle.

Instead, read the constant size once, and copy that over to the final
structure without having to re-read it again.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/fhandle.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/fs/fhandle.c
+++ b/fs/fhandle.c
@@ -195,8 +195,9 @@ static int handle_to_path(int mountdirfd
 		goto out_err;
 	}
 	/* copy the full handle */
-	if (copy_from_user(handle, ufh,
-			   sizeof(struct file_handle) +
+	*handle = f_handle;
+	if (copy_from_user(&handle->f_handle,
+			   &ufh->f_handle,
 			   f_handle.handle_bytes)) {
 		retval = -EFAULT;
 		goto out_handle;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 3.10 00/46] 3.10.80-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 07/46] net: socket: Fix the wrong returns for recvmsg and sendmsg Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 42/46] rtlwifi: rtl8192cu: Fix kernel deadlock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 36/46] rt2x00: add new rt2800usb device DWA 130 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 44/46] ACPI / init: Fix the ordering of acpi_reserve_resources() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 11/46] libceph: request a new osdmap if lingering request maps to no osd Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 19/46] ASoC: wm8960: fix "RINPUT3" audio route error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 23/46] xhci: Solve full event ring by increasing TRBS_PER_SEGMENT to 256 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 22/46] xhci: fix isoc endpoint dequeue from advancing too far on transaction error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 10/46] lguest: fix out-by-one error in address checking. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 31/46] mmc: atmel-mci: fix bad variable type for clkdiv Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 12/46] hwmon: (ntc_thermistor) Ensure iio channel is of type IIO_VOLTAGE Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 09/46] fs, omfs: add NULL terminator in the end up the token list Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 15/46] ALSA: hda - Add Conexant codecs CX20721, CX20722, CX20723 and CX20724 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 16/46] ALSA: hda - Add headphone quirk for Lifebook E752 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 14/46] d_walk() might skip too much Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 43/46] Input: elantech - fix semi-mt protocol for v3 HW Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 46/46] fs/binfmt_elf.c:load_elf_binary(): return -EINVAL on zero-length mappings Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 24/46] xhci: gracefully handle xhci_irq dead device Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 01/46] staging: wlags49_h2: fix extern inline functions Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 37/46] crypto: s390/ghash - Fix incorrect ghash icv buffer handling. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 08/46] KVM: MMU: fix CR4.SMEP=1, CR0.WP=0 with shadow pages Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 45/46] vfs: read file_handle only once in handle_to_path Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 06/46] kernel: use the gnu89 standard explicitly Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 18/46] ASoC: uda1380: Avoid accessing i2c bus when codec is disabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 13:50 +0200
  [PATCH 3.10 34/46] libata: Add helper to determine when PHY events should be ignored Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 25/46] USB: visor: Match I330 phone more precisely Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 20/46] ASoC: wm8994: correct BCLK DIV 348 to 384 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 04/46] staging: rtl8712, rtl8712: avoid lots of build warnings Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 32/46] ext4: convert write_begin methods to stable_page_writes semantics Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 30/46] powerpc: Align TOC to 256 bytes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 13/46] lib: Fix strnlen_user() to not touch memory after specified maximum Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 39/46] ARM: fix missing syscall trace exit Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 05/46] staging, rtl8192e, LLVMLinux: Remove unused inline prototype Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 03/46] staging, rtl8192e, LLVMLinux: Change extern inline to static inline Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 17/46] ASoC: mc13783: Fix wrong mask value used in mc13xxx_reg_rmw() calls Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 41/46] md/raid5: dont record new size if resize_stripes fails. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 26/46] USB: pl2303: Remove support for Samsung I330 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 29/46] usb: gadget: configfs: Fix interfaces array NULL-termination Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 33/46] ext4: check for zero length extent explicitly Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 40/46] svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  [PATCH 3.10 27/46] USB: cp210x: add ID for KCF Technologies PRN device Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-06-03 14:00 +0200
  Re: [PATCH 3.10 00/46] 3.10.80-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2015-06-03 19:00 +0200

csiph-web