user/sven/linux.git/kernel/debug, branch v5.18.19

lockdown: also lock down previous kgdb use

2022-05-30T07:24:03Z

commit eadb2f47a3ced5c64b23b90fd2a3463f63726066 upstream. KGDB and KDB allow read and write access to kernel memory, and thus should be restricted during lockdown. An attacker with access to a serial port (for example, via a hypervisor console, which some cloud vendors provide over the network) could trigger the debugger so it is important that the debugger respect the lockdown mode when/if it is triggered. Fix this by integrating lockdown into kdb's existing permissions mechanism. Unfortunately kgdb does not have any permissions mechanism (although it certainly could be added later) so, for now, kgdb is simply and brutally disabled by immediately exiting the gdb stub without taking any action. For lockdowns established early in the boot (e.g. the normal case) then this should be fine but on systems where kgdb has set breakpoints before the lockdown is enacted than "bad things" will happen. CVE: CVE-2022-21499 Co-developed-by: Stephen Brennan Signed-off-by: Stephen Brennan Reviewed-by: Douglas Anderson Signed-off-by: Daniel Thompson Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

kdb: Fix the putarea helper function

2022-03-24T16:39:47Z

Currently kdb_putarea_size() uses copy_from_kernel_nofault() to write *to* arbitrary kernel memory. This is obviously wrong and means the memory modify ('mm') command is a serious risk to debugger stability: if we poke to a bad address we'll double-fault and lose our debug session. Fix this the (very) obvious way. Note that there are two Fixes: tags because the API was renamed and this patch will only trivially backport as far as the rename (and this is probably enough). Nevertheless Christoph's rename did not introduce this problem so I wanted to record that! Fixes: fe557319aa06 ("maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault") Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Daniel Thompson Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20220128144055.207267-1-daniel.thompson@linaro.org

kdb: Adopt scheduler's task classification

2021-11-03T17:21:37Z

Currently kdb contains some open-coded routines to generate a summary character for each task. This code currently issues warnings, is almost certainly broken and won't make sense to any kernel dev who has ever used /proc to examine task states. Fix both the warning and the potential for confusion by adopting the scheduler's task classification. Whilst doing this we also simplify the filtering by using mask strings directly (which means we don't have to guess all the characters the scheduler might give us). Unfortunately we can't quite match the scheduler classification completely. We add four extra states: - for idle loops and i, m and s for sleeping system daemons (which means kthreads in one of the I, M and S states). These extra states are used to manage the filters for tools to make the output of ps and bta less noisy. Note: The Fixes below is the last point the original dubious code was moved; it was not introduced by that patch. However it gives us the last point to which this patch can be easily backported. Happily that should be enough to cover the introduction of CONFIG_WERROR! Fixes: 2f064a59a11f ("sched: Change task_struct::state") Link: https://lore.kernel.org/r/20211102173158.3315227-1-daniel.thompson@linaro.org Reviewed-by: Douglas Anderson Signed-off-by: Daniel Thompson

Merge tag 'kgdb-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux

2021-09-07T19:08:04Z

Pull kgdb updates from Daniel Thompson: "Changes for kgdb/kdb this cycle are dominated by a change from Sumit that removes as small (256K) private heap from kdb. This is change I've hoped for ever since I discovered how few users of this heap remained in the kernel, so many thanks to Sumit for hunting these down. The other change is an incremental step towards SPDX headers" * tag 'kgdb-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux: kernel: debug: Convert to SPDX identifier kdb: Rename members of struct kdbtab_t kdb: Simplify kdb_defcmd macro logic kdb: Get rid of redundant kdb_register_flags() kdb: Rename struct defcmd_set to struct kdb_macro kdb: Get rid of custom debug heap allocator

kernel: debug: Convert to SPDX identifier

2021-09-06T13:31:11Z

use SPDX-License-Identifier instead of a verbose license text Signed-off-by: Cai Huoqing Link: https://lore.kernel.org/r/20210906112302.937-1-caihuoqing@baidu.com Signed-off-by: Daniel Thompson

isystem: trim/fixup stdarg.h and other headers

2021-08-19T00:02:55Z

Delete/fixup few includes in anticipation of global -isystem compile option removal. Note: crypto/aegis128-neon-inner.c keeps due to redefinition of uintptr_t error (one definition comes from , another from ). Signed-off-by: Alexey Dobriyan Signed-off-by: Masahiro Yamada

kdb: Rename members of struct kdbtab_t

2021-07-27T16:05:06Z

Remove redundant prefix "cmd_" from name of members in struct kdbtab_t for better readibility. Suggested-by: Doug Anderson Signed-off-by: Sumit Garg Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20210712134620.276667-5-sumit.garg@linaro.org Signed-off-by: Daniel Thompson

kdb: Simplify kdb_defcmd macro logic

2021-07-27T16:04:50Z

Switch to use a linked list instead of dynamic array which makes allocation of kdb macro and traversing the kdb macro commands list simpler. Suggested-by: Daniel Thompson Signed-off-by: Sumit Garg Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20210712134620.276667-4-sumit.garg@linaro.org Signed-off-by: Daniel Thompson

kdb: Get rid of redundant kdb_register_flags()

2021-07-27T16:03:16Z

Commit e4f291b3f7bb ("kdb: Simplify kdb commands registration") allowed registration of pre-allocated kdb commands with pointer to struct kdbtab_t. Lets switch other users as well to register pre- allocated kdb commands via: - Changing prototype for kdb_register() to pass a pointer to struct kdbtab_t instead. - Embed kdbtab_t structure in kdb_macro_t rather than individual params. With these changes kdb_register_flags() becomes redundant and hence removed. Also, since we have switched all users to register pre-allocated commands, "is_dynamic" flag in struct kdbtab_t becomes redundant and hence removed as well. Suggested-by: Daniel Thompson Signed-off-by: Sumit Garg Acked-by: Steven Rostedt (VMware) Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20210712134620.276667-3-sumit.garg@linaro.org Signed-off-by: Daniel Thompson

kdb: Rename struct defcmd_set to struct kdb_macro

2021-07-27T16:00:14Z

Rename struct defcmd_set to struct kdb_macro as that sounds more appropriate given its purpose. Suggested-by: Daniel Thompson Signed-off-by: Sumit Garg Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20210712134620.276667-2-sumit.garg@linaro.org Signed-off-by: Daniel Thompson