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Zhang Zhengming 0b46ee654a relayfs: fix out-of-bounds access in relay_file_read
commit 43ec16f145 upstream.

There is a crash in relay_file_read, as the var from
point to the end of last subbuf.

The oops looks something like:
pc : __arch_copy_to_user+0x180/0x310
lr : relay_file_read+0x20c/0x2c8
Call trace:
 __arch_copy_to_user+0x180/0x310
 full_proxy_read+0x68/0x98
 vfs_read+0xb0/0x1d0
 ksys_read+0x6c/0xf0
 __arm64_sys_read+0x20/0x28
 el0_svc_common.constprop.3+0x84/0x108
 do_el0_svc+0x74/0x90
 el0_svc+0x1c/0x28
 el0_sync_handler+0x88/0xb0
 el0_sync+0x148/0x180

We get the condition by analyzing the vmcore:

1). The last produced byte and last consumed byte
    both at the end of the last subbuf

2). A softirq calls function(e.g __blk_add_trace)
    to write relay buffer occurs when an program is calling
    relay_file_read_avail().

        relay_file_read
                relay_file_read_avail
                        relay_file_read_consume(buf, 0, 0);
                        //interrupted by softirq who will write subbuf
                        ....
                        return 1;
                //read_start point to the end of the last subbuf
                read_start = relay_file_read_start_pos
                //avail is equal to subsize
                avail = relay_file_read_subbuf_avail
                //from  points to an invalid memory address
                from = buf->start + read_start
                //system is crashed
                copy_to_user(buffer, from, avail)

Link: https://lkml.kernel.org/r/20230419040203.37676-1-zhang.zhengming@h3c.com
Fixes: 8d62fdebda ("relay file read: start-pos fix")
Signed-off-by: Zhang Zhengming <zhang.zhengming@h3c.com>
Reviewed-by: Zhao Lei <zhao_lei1@hoperun.com>
Reviewed-by: Zhou Kete <zhou.kete@h3c.com>
Reviewed-by: Pengcheng Yang <yangpc@wangsu.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-11 23:00:18 +09:00
arch KVM: nVMX: Emulate NOPs in L2, and PAUSE if it's not intercepted 2023-05-11 23:00:18 +09:00
block blk-crypto: make blk_crypto_evict_key() more robust 2023-05-11 23:00:16 +09:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:22:01 +02:00
crypto crypto: api - Demote BUG_ON() in crypto_unregister_alg() to a WARN_ON() 2023-05-11 23:00:17 +09:00
Documentation riscv: Move early dtb mapping into the fixmap region 2023-05-01 08:23:24 +09:00
drivers crypto: safexcel - Cleanup ring IRQ workqueues on load failure 2023-05-11 23:00:17 +09:00
fs reiserfs: Add security prefix to xattr name in reiserfs_security_write() 2023-05-11 23:00:17 +09:00
include tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem 2023-05-11 23:00:16 +09:00
init kbuild: Add CONFIG_PAHOLE_VERSION 2023-02-25 12:06:45 +01:00
io_uring io_uring: avoid null-ptr-deref in io_arm_poll_handler 2023-03-22 13:31:37 +01:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:28:45 +01:00
kernel relayfs: fix out-of-bounds access in relay_file_read 2023-05-11 23:00:18 +09:00
lib kobject: Fix slab-out-of-bounds in fill_kobj_path() 2023-03-10 09:39:35 +01:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlock 2023-04-26 13:51:55 +02:00
net bluetooth: Perform careful capability checks in hci_sock_ioctl() 2023-05-01 08:23:23 +09:00
samples samples: vfio-mdev: Fix missing pci_disable_device() in mdpy_fb_probe() 2022-12-31 13:14:31 +01:00
scripts ASN.1: Fix check for strdup() success 2023-04-26 13:51:56 +02:00
security IMA: allow/fix UML builds 2023-05-11 23:00:16 +09:00
sound ASoC: Intel: bytcr_rt5640: Add quirk for the Acer Iconia One 7 B1-750 2023-05-11 23:00:15 +09:00
tools selftests mount: Fix mount_setattr_test builds failed 2023-05-11 23:00:15 +09:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: fix memoryleak in kvm_init() 2023-03-17 08:49:04 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS counter: Internalize sysfs interface code 2023-04-20 12:13:55 +02:00
Makefile Linux 5.15.110 2023-05-01 08:23:24 +09:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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There are various text files in the Documentation/ subdirectory,
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Please read the Documentation/process/changes.rst file, as it contains the
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