From: syzbot <syzbot+17a8efdf800000@syzkaller.appspotmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: glider@google.com, gregkh@linuxfoundation.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 4.9 08/52] vt: prevent leaking uninitialized data to userspace via /dev/vcs*
Date: Tue, 10 Jul 2018 11:30:37 -0700 [thread overview]
Message-ID: <0000000000009569c60570a953e0@google.com> (raw)
In-Reply-To: <20180710182450.302954707@linuxfoundation.org>
> 4.9-stable review patch. If anyone has any objections, please let me
> know.
> ------------------
> From: Alexander Potapenko <glider@google.com>
> commit 21eff69aaaa0e766ca0ce445b477698dc6a9f55a upstream.
> KMSAN reported an infoleak when reading from /dev/vcs*:
> BUG: KMSAN: kernel-infoleak in vcs_read+0x18ba/0x1cc0
> Call Trace:
> ...
> kmsan_copy_to_user+0x7a/0x160 mm/kmsan/kmsan.c:1253
> copy_to_user ./include/linux/uaccess.h:184
> vcs_read+0x18ba/0x1cc0 drivers/tty/vt/vc_screen.c:352
> __vfs_read+0x1b2/0x9d0 fs/read_write.c:416
> vfs_read+0x36c/0x6b0 fs/read_write.c:452
> ...
> Uninit was created at:
> kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279
> kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
> kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
> __kmalloc+0x13a/0x350 mm/slub.c:3818
> kmalloc ./include/linux/slab.h:517
> vc_allocate+0x438/0x800 drivers/tty/vt/vt.c:787
> con_install+0x8c/0x640 drivers/tty/vt/vt.c:2880
> tty_driver_install_tty drivers/tty/tty_io.c:1224
> tty_init_dev+0x1b5/0x1020 drivers/tty/tty_io.c:1324
> tty_open_by_driver drivers/tty/tty_io.c:1959
> tty_open+0x17b4/0x2ed0 drivers/tty/tty_io.c:2007
> chrdev_open+0xc25/0xd90 fs/char_dev.c:417
> do_dentry_open+0xccc/0x1440 fs/open.c:794
> vfs_open+0x1b6/0x2f0 fs/open.c:908
> ...
> Bytes 0-79 of 240 are uninitialized
> Consistently allocating |vc_screenbuf| with kzalloc() fixes the problem
> Reported-by: syzbot+17a8efdf800000@syzkaller.appspotmail.com
> Signed-off-by: Alexander Potapenko <glider@google.com>
> Cc: stable <stable@vger.kernel.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
> drivers/tty/vt/vt.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -785,7 +785,7 @@ int vc_allocate(unsigned int currcons) /
> if (!*vc->vc_uni_pagedir_loc)
> con_set_default_unimap(vc);
> - vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
> + vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
> if (!vc->vc_screenbuf)
> goto err_free;
> @@ -872,7 +872,7 @@ static int vc_do_resize(struct tty_struc
> if (new_screen_size > (4 << 20))
> return -EINVAL;
> - newscreen = kmalloc(new_screen_size, GFP_USER);
> + newscreen = kzalloc(new_screen_size, GFP_USER);
> if (!newscreen)
> return -ENOMEM;
Can't find the corresponding bug.
next prev parent reply other threads:[~2018-07-10 18:30 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-10 18:24 [PATCH 4.9 00/52] 4.9.112-stable review Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 01/52] usb: cdc_acm: Add quirk for Uniden UBC125 scanner Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 02/52] USB: serial: cp210x: add CESINEL device ids Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 03/52] USB: serial: cp210x: add Silicon Labs IDs for Windows Update Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 04/52] usb: dwc2: fix the incorrect bitmaps for the ports of multi_tt hub Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 05/52] n_tty: Fix stall at n_tty_receive_char_special() Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 06/52] n_tty: Access echo_* variables carefully Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 07/52] staging: android: ion: Return an ERR_PTR in ion_map_kernel Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 08/52] vt: prevent leaking uninitialized data to userspace via /dev/vcs* Greg Kroah-Hartman
2018-07-10 18:30 ` syzbot [this message]
2018-07-10 18:24 ` [PATCH 4.9 09/52] i2c: rcar: fix resume by always initializing registers before transfer Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 10/52] ipv4: Fix error return value in fib_convert_metrics() Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 11/52] kprobes/x86: Do not modify singlestep buffer while resuming Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 12/52] netfilter: nf_tables: use WARN_ON_ONCE instead of BUG_ON in nft_do_chain() Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 13/52] Revert "sit: reload iphdr in ipip6_rcv" Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 14/52] net: phy: micrel: fix crash when statistic requested for KSZ9031 phy Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 15/52] ARM: dts: imx6q: Use correct SDMA script for SPI5 core Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 16/52] IB/hfi1: Fix user context tail allocation for DMA_RTAIL Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 17/52] x86/xen: Add call of speculative_store_bypass_ht_init() to PV paths Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 18/52] x86/cpu: Re-apply forced caps every time CPU caps are re-read Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 19/52] mm: hugetlb: yield when prepping struct pages Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 20/52] tracing: Fix missing return symbol in function_graph output Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 21/52] scsi: sg: mitigate read/write abuse Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 22/52] s390: Correct register corruption in critical section cleanup Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 23/52] drbd: fix access after free Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 24/52] cifs: Fix infinite loop when using hard mount option Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 25/52] drm/udl: fix display corruption of the last line Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 26/52] jbd2: dont mark block as modified if the handle is out of credits Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 27/52] ext4: make sure bitmaps and the inode table dont overlap with bg descriptors Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 28/52] ext4: always check block group bounds in ext4_init_block_bitmap() Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 29/52] ext4: only look at the bg_flags field if it is valid Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 30/52] ext4: verify the depth of extent tree in ext4_find_extent() Greg Kroah-Hartman
2018-07-10 18:24 ` [PATCH 4.9 31/52] ext4: include the illegal physical block in the bad map ext4_error msg Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 32/52] ext4: clear i_data in ext4_inode_info when removing inline data Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 33/52] ext4: add more inode number paranoia checks Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 34/52] ext4: add more mount time checks of the superblock Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 35/52] ext4: check superblock mapped prior to committing Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 36/52] mlxsw: spectrum: Forbid linking of VLAN devices to devices that have uppers Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 37/52] HID: i2c-hid: Fix "incomplete report" noise Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 38/52] HID: hiddev: fix potential Spectre v1 Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 39/52] HID: debug: check length before copy_to_user() Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 40/52] PM / OPP: Update voltage in case freq == old_freq Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 41/52] Kbuild: fix # escaping in .cmd files for future Make Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 42/52] media: cx25840: Use subdev host data for PLL override Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 43/52] mm, page_alloc: do not break __GFP_THISNODE by zonelist reset Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 44/52] dm bufio: avoid sleeping while holding the dm_bufio lock Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 45/52] dm bufio: drop the lock when doing GFP_NOIO allocation Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 46/52] mtd: rawnand: mxc: set spare area size register explicitly Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 47/52] dm bufio: dont take the lock in dm_bufio_shrink_count Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 48/52] mtd: cfi_cmdset_0002: Change definition naming to retry write operation Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 49/52] mtd: cfi_cmdset_0002: Change erase functions to retry for error Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 50/52] mtd: cfi_cmdset_0002: Change erase functions to check chip good only Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 51/52] netfilter: nf_log: dont hold nf_log_mutex during user access Greg Kroah-Hartman
2018-07-10 18:25 ` [PATCH 4.9 52/52] staging: comedi: quatech_daqp_cs: fix no-op loop daqp_ao_insn_write() Greg Kroah-Hartman
2018-07-10 19:09 ` [PATCH 4.9 00/52] 4.9.112-stable review Nathan Chancellor
2018-07-11 11:04 ` Greg Kroah-Hartman
2018-07-11 11:17 ` Naresh Kamboju
2018-07-11 20:12 ` Dan Rue
2018-07-11 13:40 ` Guenter Roeck
2018-07-11 15:12 ` Shuah Khan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=0000000000009569c60570a953e0@google.com \
--to=syzbot+17a8efdf800000@syzkaller.appspotmail.com \
--cc=glider@google.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).