| Message ID | 1560156706-13617-1-git-send-email-xuyang2018.jy@cn.fujitsu.com |
|---|---|
| State | Accepted |
| Delegated to: | Petr Vorel |
| Headers | show |
| Series | [v3] sysctl/sysctl02: Add new regression test for overflow file-max | expand |
Hi, LGTM, below are just small formatting issues. I'm going to merge it with these changes below. > On upstream kernel, before commit[1], the max value in proc_get_long based on > the number of chars(21). It rejects values such as 184467440737095516160 (21 chars) > but accepts values such as 18446744073709551616 (20 chars). But we should reject all > because both are overflows. After this commit,the permitted max value is 2^64-1. > Before commit[2], when writing echo 18446744073709551616 > /proc/sys/fs/file-max > /proc/sys/fs/file-max will overflow and be set to 0. It may crash the system. This > commit sets the max and min value for file-max. After this commit,the permitted max > value is 2^63-1. > Unfortunately, commit[2] introduced the minimum value points at the global 'zero' > variable which is an int. This results in a KASAN splat when accessed as a long by > proc_doulongvec_minmax on 64-bit architectures. This bug has been fixed by commit[3]. > I will set 2^64 ,2^64-1,2^63 and 0 to file-max in case and test it. > [1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7f2923c4f73f21cfd714d12a2d48de8c21f11cfe > [2]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=32a5ad9c22852e6bd9e74bdec5934ef9d1480bc5 > [3]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9002b21465fa4d829edfc94a5a441005cffaa972 > Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com> > --- > runtest/commands | 1 + > testcases/commands/sysctl/sysctl02.sh | 96 +++++++++++++++++++++++++++ > 2 files changed, 97 insertions(+) > create mode 100755 testcases/commands/sysctl/sysctl02.sh > diff --git a/runtest/commands b/runtest/commands > index ac15e8b23..1870c4209 100644 > --- a/runtest/commands > +++ b/runtest/commands > @@ -40,3 +40,4 @@ keyctl01_sh keyctl01.sh > gdb01_sh gdb01.sh > unshare01_sh unshare01.sh > sysctl01_sh sysctl01.sh > +sysctl02_sh sysctl02.sh > diff --git a/testcases/commands/sysctl/sysctl02.sh b/testcases/commands/sysctl/sysctl02.sh > new file mode 100755 > index 000000000..22dd0a429 > --- /dev/null > +++ b/testcases/commands/sysctl/sysctl02.sh > @@ -0,0 +1,96 @@ > +#!/bin/sh > + > +# SPDX-License-Identifier: GPL-2.0-or-later > +# Copyright (c) 2019 FUJITSU LIMITED. All rights reserved. > +# Author: Yang Xu<xuyang2018.jy@cn.fujitsu.com> > +# > +# Description: > +# This is a regression test for handling overflow for file-max. Instead these 2 lines I'd put just this (nit): # Regression test for handling overflow for file-max. > +# > +# when writing 2^64 to /proc/sys/fs/file-max. It will overflow > +# and be set to 0. It crash system quickly. > +# > +# The kernel bug has been fixed in kernel: > +# '7f2923c4f' (sysctl: handle overflow in proc_get_long) > +# the permitted max value is 2^64-1. > +# '32a5ad9c2' (sysctl: handle overflow for file-max) > +# the permitted max value is 2^63-1 > +# > +# After merged this patchset, if we exceed the max value, it will > +# keep old value. Unfortunately, it introudced a new bug when set it > +# to 0 and it will lead to system crash. > +# This bug has been fixed by commit 9002b2146 > +# (kernel/sysctl.c: fix out-of-bounds access when setting file-max) > + > +TST_TESTFUNC=do_test > +TST_SETUP=setup > +TST_CLEANUP=cleanup > +TST_CNT=4 > +TST_NEEDS_ROOT=1 > +TST_NEEDS_CMDS="sysctl" > +dir="/proc/sys/fs/" > +syms_file="/proc/kallsyms" > +name="file-max" > +orig_value=200000 > + > +. tst_test.sh > + > +setup() > +{ > + [ ! -f "$dir""$name" ] && tst_brk TCONF \ > + "$name was not supported" [ ! -f "$dir$name" ] && tst_brk TCONF "$name was not supported" > + orig_value=$(cat "$dir""$name") > +} > + > +do_test() > +{ > + case $1 in > + 1)sysctl_test_overflow 18446744073709551616;; > + 2)sysctl_test_overflow 18446744073709551615;; > + 3)sysctl_test_overflow 9223372036854775808;; > + 4)sysctl_test_zero;; > + esac > +} > + > +sysctl_test_overflow() > +{ > + local old_value=$(cat "$dir""$name") > + > + sysctl -w "fs.file-max"=$1 >/dev/null 2>&1 > + > + local test_value=$(cat "$dir""$name") again, why 2 stings instead of one? local test_value=$(cat "$dir$name") > + > + echo ${test_value} |grep -q ${old_value} > + if [ $? -eq 0 ]; then > + tst_res TPASS "file-max overflow, reject it and keep old value." Please don't use dot > + else > + tst_res TFAIL "file-max overflow and set it to ${test_value}." Here as well. > + fi > + cleanup > +} > + > +sysctl_test_zero() > +{ > + sysctl -w "fs.file-max"=0 >/dev/null 2>&1 Please use -q option instead of redirecting. > + [ ! -f "$syms_file" ] && tst_brk TCONF \ > + "$syms_file was not supported" > + cat $syms_file |grep kasan_report >/dev/null 2>&1 > + if [ $? -eq 0 ]; then Also grep has -q, no need to use pipe: if grep -q kasan_report $syms_file; then > + dmesg | grep "KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax" >/dev/null -q here as well. > + if [ $? -eq 0 ]; then > + tst_res TFAIL "file-max is set 0 and trigger a KASAN error" > + else > + tst_res TPASS \ > + "file-max is set 0 and doesn't trigger a KASAN error" Probably can be on single line. > + fi > + else > + tst_res TCONF "kernel doesn't support KASAN" > + fi > +} > + > +cleanup() > +{ > + sysctl -w "fs.""$name"=${orig_value} >/dev/null 2>&1 It's safe not quote string ($name is safe, but you can of course) sysctl -q -w fs.$name=$orig_value > +} > + > +tst_run
Hi Yang, > On upstream kernel, before commit[1], the max value in proc_get_long based on > the number of chars(21). It rejects values such as 184467440737095516160 (21 chars) > but accepts values such as 18446744073709551616 (20 chars). But we should reject all > because both are overflows. After this commit,the permitted max value is 2^64-1. > Before commit[2], when writing echo 18446744073709551616 > /proc/sys/fs/file-max > /proc/sys/fs/file-max will overflow and be set to 0. It may crash the system. This > commit sets the max and min value for file-max. After this commit,the permitted max > value is 2^63-1. > Unfortunately, commit[2] introduced the minimum value points at the global 'zero' > variable which is an int. This results in a KASAN splat when accessed as a long by > proc_doulongvec_minmax on 64-bit architectures. This bug has been fixed by commit[3]. > I will set 2^64 ,2^64-1,2^63 and 0 to file-max in case and test it. > [1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7f2923c4f73f21cfd714d12a2d48de8c21f11cfe > [2]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=32a5ad9c22852e6bd9e74bdec5934ef9d1480bc5 > [3]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9002b21465fa4d829edfc94a5a441005cffaa972 Merged with adjusted commit message and following diff. Due que big changes I put my copyright there as well. Thanks for your patch! Kind regards, Petr diff --git testcases/commands/sysctl/sysctl02.sh testcases/commands/sysctl/sysctl02.sh index 22dd0a429..8a434183e 100755 --- testcases/commands/sysctl/sysctl02.sh +++ testcases/commands/sysctl/sysctl02.sh @@ -1,26 +1,18 @@ #!/bin/sh - # SPDX-License-Identifier: GPL-2.0-or-later # Copyright (c) 2019 FUJITSU LIMITED. All rights reserved. +# Copyright (c) 2019 Petr Vorel <pvorel@suse.cz> # Author: Yang Xu<xuyang2018.jy@cn.fujitsu.com> # -# Description: -# This is a regression test for handling overflow for file-max. -# -# when writing 2^64 to /proc/sys/fs/file-max. It will overflow -# and be set to 0. It crash system quickly. +# Test for these regressions causing buffer overflow when writing into +# /proc/sys/fs/file-max: +# 7f2923c4f73f ("sysctl: handle overflow in proc_get_long") +# 32a5ad9c2285 ("sysctl: handle overflow for file-max") # -# The kernel bug has been fixed in kernel: -# '7f2923c4f' (sysctl: handle overflow in proc_get_long) -# the permitted max value is 2^64-1. -# '32a5ad9c2' (sysctl: handle overflow for file-max) -# the permitted max value is 2^63-1 +# This bug has been fixed in 9002b21465fa ("kernel/sysctl.c: fix +# out-of-bounds access when setting file-max") # -# After merged this patchset, if we exceed the max value, it will -# keep old value. Unfortunately, it introudced a new bug when set it -# to 0 and it will lead to system crash. -# This bug has been fixed by commit 9002b2146 -# (kernel/sysctl.c: fix out-of-bounds access when setting file-max) +# We test in sysctl02.sh setting 2^64, 2^64-1, 2^63 and 0. TST_TESTFUNC=do_test TST_SETUP=setup @@ -28,60 +20,52 @@ TST_CLEANUP=cleanup TST_CNT=4 TST_NEEDS_ROOT=1 TST_NEEDS_CMDS="sysctl" -dir="/proc/sys/fs/" +sys_name="fs.file-max" +sys_file="/proc/sys/fs/file-max" syms_file="/proc/kallsyms" -name="file-max" -orig_value=200000 . tst_test.sh setup() { - [ ! -f "$dir""$name" ] && tst_brk TCONF \ - "$name was not supported" - orig_value=$(cat "$dir""$name") + [ ! -f "$sys_file" ] && tst_brk TCONF "$sys_file not enabled" + orig_value=$(cat "$sys_file") } do_test() { case $1 in - 1)sysctl_test_overflow 18446744073709551616;; - 2)sysctl_test_overflow 18446744073709551615;; - 3)sysctl_test_overflow 9223372036854775808;; - 4)sysctl_test_zero;; + 1) sysctl_test_overflow 18446744073709551616 ;; + 2) sysctl_test_overflow 18446744073709551615 ;; + 3) sysctl_test_overflow 9223372036854775808 ;; + 4) sysctl_test_zero ;; esac } sysctl_test_overflow() { - local old_value=$(cat "$dir""$name") - - sysctl -w "fs.file-max"=$1 >/dev/null 2>&1 + local old_value="$(cat $sys_file)" + sysctl -w -q $sys_name=$1 2>/dev/null + local test_value="$(cat $sys_file)" - local test_value=$(cat "$dir""$name") - - echo ${test_value} |grep -q ${old_value} - if [ $? -eq 0 ]; then - tst_res TPASS "file-max overflow, reject it and keep old value." + if echo $test_value | grep -q $old_value; then + tst_res TPASS "$sys_file overflows, reject it and keep old value" else - tst_res TFAIL "file-max overflow and set it to ${test_value}." + tst_res TFAIL "$sys_file overflows and set to $test_value" fi cleanup } sysctl_test_zero() { - sysctl -w "fs.file-max"=0 >/dev/null 2>&1 - [ ! -f "$syms_file" ] && tst_brk TCONF \ - "$syms_file was not supported" - cat $syms_file |grep kasan_report >/dev/null 2>&1 - if [ $? -eq 0 ]; then - dmesg | grep "KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax" >/dev/null - if [ $? -eq 0 ]; then - tst_res TFAIL "file-max is set 0 and trigger a KASAN error" + [ ! -f "$syms_file" ] && tst_brk TCONF "$syms_file not enabled" + ROD sysctl -w -q $sys_name=0 + + if grep -q kasan_report $syms_file; then + if dmesg | grep -q "KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax"; then + tst_res TFAIL "$sys_file is set 0 and trigger a KASAN error" else - tst_res TPASS \ - "file-max is set 0 and doesn't trigger a KASAN error" + tst_res TPASS "$sys_file is set 0 and doesn't trigger a KASAN error" fi else tst_res TCONF "kernel doesn't support KASAN" @@ -90,7 +74,7 @@ sysctl_test_zero() cleanup() { - sysctl -w "fs.""$name"=${orig_value} >/dev/null 2>&1 + [ -n "$orig_value" ] && sysctl -w -q $sys_name=$orig_value } tst_run
> Hi, > > LGTM, below are just small formatting issues. > I'm going to merge it with these changes below. > >> Signed-off-by: Yang Xu<xuyang2018.jy@cn.fujitsu.com> >> --- >> runtest/commands | 1 + >> testcases/commands/sysctl/sysctl02.sh | 96 +++++++++++++++++++++++++++ >> 2 files changed, 97 insertions(+) >> create mode 100755 testcases/commands/sysctl/sysctl02.sh > ... >> +sysctl_test_overflow() >> +{ >> + local old_value=$(cat "$dir""$name") >> + >> + sysctl -w "fs.file-max"=$1>/dev/null 2>&1 >> + >> + local test_value=$(cat "$dir""$name") > again, why 2 stings instead of one? > local test_value=$(cat "$dir$name") Hi Petr I use 2 strings because sysctl uses "fs.file-max" but cat uses "fs/file-max" file. Your big changes look good to me. Thanks for your changes. >> + >> + echo ${test_value} |grep -q ${old_value} >> + if [ $? -eq 0 ]; then >> + tst_res TPASS "file-max overflow, reject it and keep old value." > Please don't use dot > >> + else >> + tst_res TFAIL "file-max overflow and set it to ${test_value}." > Here as well. > >> + fi >> + cleanup >> +} >> + >> +sysctl_test_zero() >> +{ >> + sysctl -w "fs.file-max"=0>/dev/null 2>&1 > Please use -q option instead of redirecting. >> + [ ! -f "$syms_file" ]&& tst_brk TCONF \ >> + "$syms_file was not supported" >> + cat $syms_file |grep kasan_report>/dev/null 2>&1 >> + if [ $? -eq 0 ]; then > Also grep has -q, no need to use pipe: > > if grep -q kasan_report $syms_file; then > >> + dmesg | grep "KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax">/dev/null > -q here as well. > >> + if [ $? -eq 0 ]; then >> + tst_res TFAIL "file-max is set 0 and trigger a KASAN error" >> + else >> + tst_res TPASS \ >> + "file-max is set 0 and doesn't trigger a KASAN error" > Probably can be on single line. > >> + fi >> + else >> + tst_res TCONF "kernel doesn't support KASAN" >> + fi >> +} >> + >> +cleanup() >> +{ >> + sysctl -w "fs.""$name"=${orig_value}>/dev/null 2>&1 > It's safe not quote string ($name is safe, but you can of course) > sysctl -q -w fs.$name=$orig_value > >> +} >> + >> +tst_run > > . >
Hi Yang, > Hi Petr > I use 2 strings because sysctl uses "fs.file-max" but cat uses "fs/file-max" file. > Your big changes look good to me. Thanks for your changes. I pushed tiny changes to sysctl02.sh as 8e2d73a88 ("sysctl/sysctl02: Improve log messages"). See the diff below. Kind regards, Petr diff --git a/testcases/commands/sysctl/sysctl02.sh b/testcases/commands/sysctl/sysctl02.sh index 8a434183e..3964a9829 100755 --- a/testcases/commands/sysctl/sysctl02.sh +++ b/testcases/commands/sysctl/sysctl02.sh @@ -44,14 +44,17 @@ do_test() sysctl_test_overflow() { + local test_value="$1" local old_value="$(cat $sys_file)" - sysctl -w -q $sys_name=$1 2>/dev/null - local test_value="$(cat $sys_file)" - if echo $test_value | grep -q $old_value; then - tst_res TPASS "$sys_file overflows, reject it and keep old value" + tst_res TINFO "trying to set $sys_name=$test_value" + sysctl -w -q $sys_name=$test_value 2>/dev/null + local new_value="$(cat $sys_file)" + + if [ "$new_value" = "$old_value" ]; then + tst_res TPASS "$sys_file keeps old value ($old_value)" else - tst_res TFAIL "$sys_file overflows and set to $test_value" + tst_res TFAIL "$sys_file overflows and is set to $new_value" fi cleanup }
> Hi Yang, > >> Hi Petr >> I use 2 strings because sysctl uses "fs.file-max" but cat uses "fs/file-max" file. >> Your big changes look good to me. Thanks for your changes. > I pushed tiny changes to sysctl02.sh as 8e2d73a88 ("sysctl/sysctl02: Improve log messages"). > See the diff below. Hi Petr Your change makes this case more clear for user. It looks good to me. Thanks Yang Xu > Kind regards, > Petr > > diff --git a/testcases/commands/sysctl/sysctl02.sh b/testcases/commands/sysctl/sysctl02.sh > index 8a434183e..3964a9829 100755 > --- a/testcases/commands/sysctl/sysctl02.sh > +++ b/testcases/commands/sysctl/sysctl02.sh > @@ -44,14 +44,17 @@ do_test() > > sysctl_test_overflow() > { > + local test_value="$1" > local old_value="$(cat $sys_file)" > - sysctl -w -q $sys_name=$1 2>/dev/null > - local test_value="$(cat $sys_file)" > > - if echo $test_value | grep -q $old_value; then > - tst_res TPASS "$sys_file overflows, reject it and keep old value" > + tst_res TINFO "trying to set $sys_name=$test_value" > + sysctl -w -q $sys_name=$test_value 2>/dev/null > + local new_value="$(cat $sys_file)" > + > + if [ "$new_value" = "$old_value" ]; then > + tst_res TPASS "$sys_file keeps old value ($old_value)" > else > - tst_res TFAIL "$sys_file overflows and set to $test_value" > + tst_res TFAIL "$sys_file overflows and is set to $new_value" > fi > cleanup > } > > > . >
diff --git a/runtest/commands b/runtest/commands index ac15e8b23..1870c4209 100644 --- a/runtest/commands +++ b/runtest/commands @@ -40,3 +40,4 @@ keyctl01_sh keyctl01.sh gdb01_sh gdb01.sh unshare01_sh unshare01.sh sysctl01_sh sysctl01.sh +sysctl02_sh sysctl02.sh diff --git a/testcases/commands/sysctl/sysctl02.sh b/testcases/commands/sysctl/sysctl02.sh new file mode 100755 index 000000000..22dd0a429 --- /dev/null +++ b/testcases/commands/sysctl/sysctl02.sh @@ -0,0 +1,96 @@ +#!/bin/sh + +# SPDX-License-Identifier: GPL-2.0-or-later +# Copyright (c) 2019 FUJITSU LIMITED. All rights reserved. +# Author: Yang Xu<xuyang2018.jy@cn.fujitsu.com> +# +# Description: +# This is a regression test for handling overflow for file-max. +# +# when writing 2^64 to /proc/sys/fs/file-max. It will overflow +# and be set to 0. It crash system quickly. +# +# The kernel bug has been fixed in kernel: +# '7f2923c4f' (sysctl: handle overflow in proc_get_long) +# the permitted max value is 2^64-1. +# '32a5ad9c2' (sysctl: handle overflow for file-max) +# the permitted max value is 2^63-1 +# +# After merged this patchset, if we exceed the max value, it will +# keep old value. Unfortunately, it introudced a new bug when set it +# to 0 and it will lead to system crash. +# This bug has been fixed by commit 9002b2146 +# (kernel/sysctl.c: fix out-of-bounds access when setting file-max) + +TST_TESTFUNC=do_test +TST_SETUP=setup +TST_CLEANUP=cleanup +TST_CNT=4 +TST_NEEDS_ROOT=1 +TST_NEEDS_CMDS="sysctl" +dir="/proc/sys/fs/" +syms_file="/proc/kallsyms" +name="file-max" +orig_value=200000 + +. tst_test.sh + +setup() +{ + [ ! -f "$dir""$name" ] && tst_brk TCONF \ + "$name was not supported" + orig_value=$(cat "$dir""$name") +} + +do_test() +{ + case $1 in + 1)sysctl_test_overflow 18446744073709551616;; + 2)sysctl_test_overflow 18446744073709551615;; + 3)sysctl_test_overflow 9223372036854775808;; + 4)sysctl_test_zero;; + esac +} + +sysctl_test_overflow() +{ + local old_value=$(cat "$dir""$name") + + sysctl -w "fs.file-max"=$1 >/dev/null 2>&1 + + local test_value=$(cat "$dir""$name") + + echo ${test_value} |grep -q ${old_value} + if [ $? -eq 0 ]; then + tst_res TPASS "file-max overflow, reject it and keep old value." + else + tst_res TFAIL "file-max overflow and set it to ${test_value}." + fi + cleanup +} + +sysctl_test_zero() +{ + sysctl -w "fs.file-max"=0 >/dev/null 2>&1 + [ ! -f "$syms_file" ] && tst_brk TCONF \ + "$syms_file was not supported" + cat $syms_file |grep kasan_report >/dev/null 2>&1 + if [ $? -eq 0 ]; then + dmesg | grep "KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax" >/dev/null + if [ $? -eq 0 ]; then + tst_res TFAIL "file-max is set 0 and trigger a KASAN error" + else + tst_res TPASS \ + "file-max is set 0 and doesn't trigger a KASAN error" + fi + else + tst_res TCONF "kernel doesn't support KASAN" + fi +} + +cleanup() +{ + sysctl -w "fs.""$name"=${orig_value} >/dev/null 2>&1 +} + +tst_run
On upstream kernel, before commit[1], the max value in proc_get_long based on the number of chars(21). It rejects values such as 184467440737095516160 (21 chars) but accepts values such as 18446744073709551616 (20 chars). But we should reject all because both are overflows. After this commit,the permitted max value is 2^64-1. Before commit[2], when writing echo 18446744073709551616 > /proc/sys/fs/file-max /proc/sys/fs/file-max will overflow and be set to 0. It may crash the system. This commit sets the max and min value for file-max. After this commit,the permitted max value is 2^63-1. Unfortunately, commit[2] introduced the minimum value points at the global 'zero' variable which is an int. This results in a KASAN splat when accessed as a long by proc_doulongvec_minmax on 64-bit architectures. This bug has been fixed by commit[3]. I will set 2^64 ,2^64-1,2^63 and 0 to file-max in case and test it. [1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7f2923c4f73f21cfd714d12a2d48de8c21f11cfe [2]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=32a5ad9c22852e6bd9e74bdec5934ef9d1480bc5 [3]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9002b21465fa4d829edfc94a5a441005cffaa972 Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com> --- runtest/commands | 1 + testcases/commands/sysctl/sysctl02.sh | 96 +++++++++++++++++++++++++++ 2 files changed, 97 insertions(+) create mode 100755 testcases/commands/sysctl/sysctl02.sh