linux-stable.git/kernel/debug, branch v5.4.280 Linux kernel stable tree kdb: Use format-specifiers rather than memset() for padding in kdb_read() 2024-06-16T11:28:52+00:00 Daniel Thompson daniel.thompson@linaro.org 2024-04-24T14:03:38+00:00 6b84387afe8064008bcb82b71694d2262e058f72 commit c9b51ddb66b1d96e4d364c088da0f1dfb004c574 upstream. Currently when the current line should be removed from the display kdb_read() uses memset() to fill a temporary buffer with spaces. The problem is not that this could be trivially implemented using a format string rather than open coding it. The real problem is that it is possible, on systems with a long kdb_prompt_str, to write past the end of the tmpbuffer. Happily, as mentioned above, this can be trivially implemented using a format string. Make it so! Cc: stable@vger.kernel.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-5-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c9b51ddb66b1d96e4d364c088da0f1dfb004c574 upstream.

Currently when the current line should be removed from the display
kdb_read() uses memset() to fill a temporary buffer with spaces.
The problem is not that this could be trivially implemented using a
format string rather than open coding it. The real problem is that
it is possible, on systems with a long kdb_prompt_str, to write past
the end of the tmpbuffer.

Happily, as mentioned above, this can be trivially implemented using a
format string. Make it so!

Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-5-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kdb: Merge identical case statements in kdb_read() 2024-06-16T11:28:52+00:00 Daniel Thompson daniel.thompson@linaro.org 2024-04-24T14:03:37+00:00 147bac05f28ca848390f5eee0f53f39e37b852b8 commit 6244917f377bf64719551b58592a02a0336a7439 upstream. The code that handles case 14 (down) and case 16 (up) has been copy and pasted despite being byte-for-byte identical. Combine them. Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-4-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6244917f377bf64719551b58592a02a0336a7439 upstream.

The code that handles case 14 (down) and case 16 (up) has been copy and
pasted despite being byte-for-byte identical. Combine them.

Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-4-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kdb: Fix console handling when editing and tab-completing commands 2024-06-16T11:28:52+00:00 Daniel Thompson daniel.thompson@linaro.org 2024-04-24T14:03:36+00:00 084e84ede9eb492e5a495a60ad14a2b3747db7e3 commit db2f9c7dc29114f531df4a425d0867d01e1f1e28 upstream. Currently, if the cursor position is not at the end of the command buffer and the user uses the Tab-complete functions, then the console does not leave the cursor in the correct position. For example consider the following buffer with the cursor positioned at the ^: md kdb_pro 10 ^ Pressing tab should result in: md kdb_prompt_str 10 ^ However this does not happen. Instead the cursor is placed at the end (after then 10) and further cursor movement redraws incorrectly. The same problem exists when we double-Tab but in a different part of the code. Fix this by sending a carriage return and then redisplaying the text to the left of the cursor. Cc: stable@vger.kernel.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-3-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit db2f9c7dc29114f531df4a425d0867d01e1f1e28 upstream.

Currently, if the cursor position is not at the end of the command buffer
and the user uses the Tab-complete functions, then the console does not
leave the cursor in the correct position.

For example consider the following buffer with the cursor positioned
at the ^:

md kdb_pro 10
          ^

Pressing tab should result in:

md kdb_prompt_str 10
                 ^

However this does not happen. Instead the cursor is placed at the end
(after then 10) and further cursor movement redraws incorrectly. The
same problem exists when we double-Tab but in a different part of the
code.

Fix this by sending a carriage return and then redisplaying the text to
the left of the cursor.

Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-3-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kdb: Use format-strings rather than '\0' injection in kdb_read() 2024-06-16T11:28:51+00:00 Daniel Thompson daniel.thompson@linaro.org 2024-04-24T14:03:35+00:00 6a3836f29bc5931f8c648683b31a9cf6ad7e68f0 commit 09b35989421dfd5573f0b4683c7700a7483c71f9 upstream. Currently when kdb_read() needs to reposition the cursor it uses copy and paste code that works by injecting an '\0' at the cursor position before delivering a carriage-return and reprinting the line (which stops at the '\0'). Tidy up the code by hoisting the copy and paste code into an appropriately named function. Additionally let's replace the '\0' injection with a proper field width parameter so that the string will be abridged during formatting instead. Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes Tested-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-2-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 09b35989421dfd5573f0b4683c7700a7483c71f9 upstream.

Currently when kdb_read() needs to reposition the cursor it uses copy and
paste code that works by injecting an '\0' at the cursor position before
delivering a carriage-return and reprinting the line (which stops at the
'\0').

Tidy up the code by hoisting the copy and paste code into an appropriately
named function. Additionally let's replace the '\0' injection with a
proper field width parameter so that the string will be abridged during
formatting instead.

Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes
Tested-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-2-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kdb: Fix buffer overflow during tab-complete 2024-06-16T11:28:51+00:00 Daniel Thompson daniel.thompson@linaro.org 2024-04-24T14:03:34+00:00 ddd2972d8e2dee3b33e8121669d55def59f0be8a commit e9730744bf3af04cda23799029342aa3cddbc454 upstream. Currently, when the user attempts symbol completion with the Tab key, kdb will use strncpy() to insert the completed symbol into the command buffer. Unfortunately it passes the size of the source buffer rather than the destination to strncpy() with predictably horrible results. Most obviously if the command buffer is already full but cp, the cursor position, is in the middle of the buffer, then we will write past the end of the supplied buffer. Fix this by replacing the dubious strncpy() calls with memmove()/memcpy() calls plus explicit boundary checks to make sure we have enough space before we start moving characters around. Reported-by: Justin Stitt <justinstitt@google.com> Closes: https://lore.kernel.org/all/CAFhGd8qESuuifuHsNjFPR-Va3P80bxrw+LqvC8deA8GziUJLpw@mail.gmail.com/ Cc: stable@vger.kernel.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Justin Stitt <justinstitt@google.com> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-1-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e9730744bf3af04cda23799029342aa3cddbc454 upstream.

Currently, when the user attempts symbol completion with the Tab key, kdb
will use strncpy() to insert the completed symbol into the command buffer.
Unfortunately it passes the size of the source buffer rather than the
destination to strncpy() with predictably horrible results. Most obviously
if the command buffer is already full but cp, the cursor position, is in
the middle of the buffer, then we will write past the end of the supplied
buffer.

Fix this by replacing the dubious strncpy() calls with memmove()/memcpy()
calls plus explicit boundary checks to make sure we have enough space
before we start moving characters around.

Reported-by: Justin Stitt <justinstitt@google.com>
Closes: https://lore.kernel.org/all/CAFhGd8qESuuifuHsNjFPR-Va3P80bxrw+LqvC8deA8GziUJLpw@mail.gmail.com/
Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Tested-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-1-f236dbe9828d@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kdb: Fix a potential buffer overflow in kdb_local() 2024-01-25T22:34:32+00:00 Christophe JAILLET christophe.jaillet@wanadoo.fr 2023-11-25T12:05:04+00:00 d5661f46c11d557a1bc342b697bc4b5823a64c03 [ Upstream commit 4f41d30cd6dc865c3cbc1a852372321eba6d4e4c ] When appending "[defcmd]" to 'kdb_prompt_str', the size of the string already in the buffer should be taken into account. An option could be to switch from strncat() to strlcat() which does the correct test to avoid such an overflow. However, this actually looks as dead code, because 'defcmd_in_progress' can't be true here. See a more detailed explanation at [1]. [1]: https://lore.kernel.org/all/CAD=FV=WSh7wKN7Yp-3wWiDgX4E3isQ8uh0LCzTmd1v9Cg9j+nQ@mail.gmail.com/ Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4f41d30cd6dc865c3cbc1a852372321eba6d4e4c ]

When appending "[defcmd]" to 'kdb_prompt_str', the size of the string
already in the buffer should be taken into account.

An option could be to switch from strncat() to strlcat() which does the
correct test to avoid such an overflow.

However, this actually looks as dead code, because 'defcmd_in_progress'
can't be true here.
See a more detailed explanation at [1].

[1]: https://lore.kernel.org/all/CAD=FV=WSh7wKN7Yp-3wWiDgX4E3isQ8uh0LCzTmd1v9Cg9j+nQ@mail.gmail.com/

Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
kdb: Censor attempts to set PROMPT without ENABLE_MEM_READ 2024-01-25T22:34:32+00:00 Daniel Thompson daniel.thompson@linaro.org 2020-02-13T15:16:40+00:00 cf6260a34d28492fc300923b59acfa4a4c5029ad [ Upstream commit ad99b5105c0823ff02126497f4366e6a8009453e ] Currently the PROMPT variable could be abused to provoke the printf() machinery to read outside the current stack frame. Normally this doesn't matter becaues md is already a much better tool for reading from memory. However the md command can be disabled by not setting KDB_ENABLE_MEM_READ. Let's also prevent PROMPT from being modified in these circumstances. Whilst adding a comment to help future code reviewers we also remove the #ifdef where PROMPT in consumed. There is no problem passing an unused (0) to snprintf when !CONFIG_SMP. argument Reported-by: Wang Xiayang <xywang.sjtu@sjtu.edu.cn> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Stable-dep-of: 4f41d30cd6dc ("kdb: Fix a potential buffer overflow in kdb_local()") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ad99b5105c0823ff02126497f4366e6a8009453e ]

Currently the PROMPT variable could be abused to provoke the printf()
machinery to read outside the current stack frame. Normally this
doesn't matter becaues md is already a much better tool for reading
from memory.

However the md command can be disabled by not setting KDB_ENABLE_MEM_READ.
Let's also prevent PROMPT from being modified in these circumstances.

Whilst adding a comment to help future code reviewers we also remove
the #ifdef where PROMPT in consumed. There is no problem passing an
unused (0) to snprintf when !CONFIG_SMP.
argument

Reported-by: Wang Xiayang <xywang.sjtu@sjtu.edu.cn>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Stable-dep-of: 4f41d30cd6dc ("kdb: Fix a potential buffer overflow in kdb_local()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
kgdb: Flush console before entering kgdb on panic 2023-11-28T16:50:16+00:00 Douglas Anderson dianders@chromium.org 2023-08-22T20:19:46+00:00 6d703922bc9e430f6bda3dddeff65923e9babce9 [ Upstream commit dd712d3d45807db9fcae28a522deee85c1f2fde6 ] When entering kdb/kgdb on a kernel panic, it was be observed that the console isn't flushed before the `kdb` prompt came up. Specifically, when using the buddy lockup detector on arm64 and running: echo HARDLOCKUP > /sys/kernel/debug/provoke-crash/DIRECT I could see: [ 26.161099] lkdtm: Performing direct entry HARDLOCKUP [ 32.499881] watchdog: Watchdog detected hard LOCKUP on cpu 6 [ 32.552865] Sending NMI from CPU 5 to CPUs 6: [ 32.557359] NMI backtrace for cpu 6 ... [backtrace for cpu 6] ... [ 32.558353] NMI backtrace for cpu 5 ... [backtrace for cpu 5] ... [ 32.867471] Sending NMI from CPU 5 to CPUs 0-4,7: [ 32.872321] NMI backtrace forP cpuANC: Hard LOCKUP Entering kdb (current=..., pid 0) on processor 5 due to Keyboard Entry [5]kdb> As you can see, backtraces for the other CPUs start printing and get interleaved with the kdb PANIC print. Let's replicate the commands to flush the console in the kdb panic entry point to avoid this. Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230822131945.1.I5b460ae8f954e4c4f628a373d6e74713c06dd26f@changeid Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit dd712d3d45807db9fcae28a522deee85c1f2fde6 ]

When entering kdb/kgdb on a kernel panic, it was be observed that the
console isn't flushed before the `kdb` prompt came up. Specifically,
when using the buddy lockup detector on arm64 and running:
  echo HARDLOCKUP > /sys/kernel/debug/provoke-crash/DIRECT

I could see:
  [   26.161099] lkdtm: Performing direct entry HARDLOCKUP
  [   32.499881] watchdog: Watchdog detected hard LOCKUP on cpu 6
  [   32.552865] Sending NMI from CPU 5 to CPUs 6:
  [   32.557359] NMI backtrace for cpu 6
  ... [backtrace for cpu 6] ...
  [   32.558353] NMI backtrace for cpu 5
  ... [backtrace for cpu 5] ...
  [   32.867471] Sending NMI from CPU 5 to CPUs 0-4,7:
  [   32.872321] NMI backtrace forP cpuANC: Hard LOCKUP

  Entering kdb (current=..., pid 0) on processor 5 due to Keyboard Entry
  [5]kdb>

As you can see, backtraces for the other CPUs start printing and get
interleaved with the kdb PANIC print.

Let's replicate the commands to flush the console in the kdb panic
entry point to avoid this.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230822131945.1.I5b460ae8f954e4c4f628a373d6e74713c06dd26f@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD() 2023-04-20T10:07:32+00:00 Kees Cook keescook@chromium.org 2020-07-13T22:01:26+00:00 2e64d7b182c6e0ec7ca239f8e79f3f01a6a60f4a [ Upstream commit b13fecb1c3a603c4b8e99b306fecf4f668c11b32 ] This converts all the existing DECLARE_TASKLET() (and ...DISABLED) macros with DECLARE_TASKLET_OLD() in preparation for refactoring the tasklet callback type. All existing DECLARE_TASKLET() users had a "0" data argument, it has been removed here as well. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Kees Cook <keescook@chromium.org> Stable-dep-of: 1fdeb8b9f29d ("wifi: iwl3945: Add missing check for create_singlethread_workqueue") Signed-off-by: Sasha Levin <sashal@kernel.org> [Tom: fix backport to 5.4.y] AUTOSEL backport to 5.4.y of: b13fecb1c3a6 ("treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()") changed all locations of DECLARE_TASKLET with DECLARE_TASKLET_OLD, except one, in arch/mips/lasat/pcivue_proc.c. This is due to: 10760dde9be3 ("MIPS: Remove support for LASAT") preceeding b13fecb1c3a6 ("treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()") upstream and the former not being present in 5.4.y. Fix this by changing DECLARE_TASKLET to DECLARE_TASKLET_OLD in arch/mips/lasat/pcivue_proc.c. Fixes: 5de7a4254eb2 ("treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()") Reported-by: "kernelci.org bot" <bot@kernelci.org> Signed-off-by: Tom Saeger <tom.saeger@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit b13fecb1c3a603c4b8e99b306fecf4f668c11b32 ]

This converts all the existing DECLARE_TASKLET() (and ...DISABLED)
macros with DECLARE_TASKLET_OLD() in preparation for refactoring the
tasklet callback type. All existing DECLARE_TASKLET() users had a "0"
data argument, it has been removed here as well.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Stable-dep-of: 1fdeb8b9f29d ("wifi: iwl3945: Add missing check for create_singlethread_workqueue")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[Tom: fix backport to 5.4.y]

AUTOSEL backport to 5.4.y of:
b13fecb1c3a6 ("treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()")
changed all locations of DECLARE_TASKLET with DECLARE_TASKLET_OLD,
except one, in arch/mips/lasat/pcivue_proc.c.

This is due to:
10760dde9be3 ("MIPS: Remove support for LASAT") preceeding
b13fecb1c3a6 ("treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()")
upstream and the former not being present in 5.4.y.

Fix this by changing DECLARE_TASKLET to DECLARE_TASKLET_OLD in
arch/mips/lasat/pcivue_proc.c.

Fixes: 5de7a4254eb2 ("treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()" 2023-04-20T10:07:32+00:00 Tom Saeger tom.saeger@oracle.com 2023-03-17T14:25:30+00:00 199197660bdd7c5b84ed50b382ed6252b6d10ccb This reverts commit 5de7a4254eb2d501cbb59918a152665b29c02109 which caused mips build failures. kernelci.org bot reports: arch/mips/lasat/picvue_proc.c:87:20: error: ‘pvc_display_tasklet’ undeclared (first use in this function) arch/mips/lasat/picvue_proc.c:42:44: error: expected ‘)’ before ‘&’ token arch/mips/lasat/picvue_proc.c:33:13: error: ‘pvc_display’ defined but not used [-Werror=unused-function] Link: https://lore.kernel.org/stable/64041dda.170a0220.8cc25.79c9@mx.google.com/ Reported-by: "kernelci.org bot" <bot@kernelci.org> Signed-off-by: Tom Saeger <tom.saeger@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This reverts commit 5de7a4254eb2d501cbb59918a152665b29c02109 which
caused mips build failures.

kernelci.org bot reports:

arch/mips/lasat/picvue_proc.c:87:20: error: ‘pvc_display_tasklet’ undeclared
(first use in this function)
arch/mips/lasat/picvue_proc.c:42:44: error: expected ‘)’ before ‘&’ token
arch/mips/lasat/picvue_proc.c:33:13: error: ‘pvc_display’ defined but not used
[-Werror=unused-function]

Link: https://lore.kernel.org/stable/64041dda.170a0220.8cc25.79c9@mx.google.com/
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>