From: Marco Felsch <m.felsch@pengutronix.de> To: oss-tools@pengutronix.de Cc: mfe@pengutronix.de Subject: [OSS-Tools] [PATCH dt-utils 03/14] state: backend_storage: deal gracefully with runtime bucket corruption Date: Fri, 14 Oct 2022 18:41:53 +0200 [thread overview] Message-ID: <20221014164204.3812506-4-m.felsch@pengutronix.de> (raw) In-Reply-To: <20221014164204.3812506-1-m.felsch@pengutronix.de> This ports the following barebox commit | commit dc5100e6ba686fafd5570ce6d972383f047c7313 | Author: Ahmad Fatoum <a.fatoum@pengutronix.de> | Date: Thu Mar 5 08:40:31 2020 +0100 | | state: backend_storage: deal gracefully with runtime bucket corruption | | Corrupting an already selected bucket and then reading it again will | crash barebox when it attempts the refresh: | | barebox$ state -l | barebox$ mw -d /dev/eeprom0.state 0 0x42 | barebox$ state -l | ERROR: state: No meta data header found | state: Using bucket 1@0x00000040 | unable to handle NULL pointer dereference at address 0x00000000 | pc : [<4fe4f1ea>] lr : [<4fe0bcb1>] | sp : 4ffefd5c ip : 00000000 fp : 2ff68f04 | r10: 4ffefdc8 r9 : 4b434d63 r8 : 30155f50 | r7 : 00000024 r6 : 2ff68b60 r5 : 2ff68e90 r4 : 00000000 | r3 : 00000024 r2 : 00000024 r1 : 30155f50 r0 : 00000000 | Flags: Nzcv IRQs off FIQs off Mode SVC_32 | WARNING: [<4fe4f1ea>] (memcmp+0x14/0x1a) from [<4fe0bcb1>] (bucket_refresh.isra.0+0x4d/0x78) | WARNING: [<4fe0bcb1>] (bucket_refresh.isra.0+0x4d/0x78) from [<4fe0be1d>] (state_storage_read+0xd1/0x104) | WARNING: [<4fe0be1d>] (state_storage_read+0xd1/0x104) from [<4fe0a5bd>] (state_do_load+0x1d/0x78) | WARNING: [<4fe0a5bd>] (state_do_load+0x1d/0x78) from [<4fe04137>] (execute_command+0x23/0x4c) | | The memcmp called here is an optimization to skip I/O if the used bucket | and the one to be refreshed compare equal. Unfortunately, if the now | corrupt bucket was previously the used one, bucket->len will hold the | old value and we'll run into a NULL pointer dereference. | | While this is quite inconvenient, it appears it doesn't affect | correctness: after the reset, the corrupt bucket will be refreshed | as expected. | | Improve upon this by setting the length to zero when we are NULLing the | buffer. The zero length of the corrupted bucket will then compare unequal | to used_bucket->len in bucket_refresh() and ensure we will always refresh | the buffer if it becomes corrupted without an intermittent reset. | | Fixes: 238008b4bd8f ("state: Drop cache bucket") | Cc: Enrico Jörns <ejo@pengutronix.de> | Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> | Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> --- src/barebox-state/backend_storage.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/barebox-state/backend_storage.c b/src/barebox-state/backend_storage.c index 509427f..458f2a9 100644 --- a/src/barebox-state/backend_storage.c +++ b/src/barebox-state/backend_storage.c @@ -192,6 +192,7 @@ int state_storage_read(struct state_backend_storage *storage, /* Free buffer from the unused buckets */ free(bucket->buf); bucket->buf = NULL; + bucket->len = 0; } /* @@ -204,6 +205,7 @@ int state_storage_read(struct state_backend_storage *storage, /* buffer from the used bucket is passed to the caller, do not free */ bucket_used->buf = NULL; + bucket_used->len = 0; return 0; } -- 2.30.2
next prev parent reply other threads:[~2022-10-14 16:42 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-10-14 16:41 [OSS-Tools] [PATCH dt-utils 00/14] Sync Barebox-State code base Marco Felsch 2022-10-14 16:41 ` [OSS-Tools] [PATCH dt-utils 01/14] state: Remove duplicate incudes Marco Felsch 2022-10-14 16:41 ` [OSS-Tools] [PATCH dt-utils 02/14] state: backend_raw: fix ignoring unpack failures Marco Felsch 2022-10-14 16:41 ` Marco Felsch [this message] 2022-10-14 16:41 ` [OSS-Tools] [PATCH dt-utils 04/14] state: treat state with all-invalid buckets as dirty Marco Felsch 2022-10-14 16:41 ` [OSS-Tools] [PATCH dt-utils 05/14] state: remove param member from struct state_string Marco Felsch 2022-10-14 16:41 ` [OSS-Tools] [PATCH dt-utils 06/14] state: remove param member from state_uint32, state_enum32, state_mac Marco Felsch 2022-10-14 16:41 ` [OSS-Tools] [PATCH dt-utils 07/14] state: remove unused function Marco Felsch 2022-10-14 16:41 ` [OSS-Tools] [PATCH dt-utils 08/14] state: propagate failure to fixup enum32 into DT Marco Felsch 2022-10-14 16:41 ` [OSS-Tools] [PATCH dt-utils 09/14] state: add SPDX-License-Identifier for files without explicit license Marco Felsch 2022-10-14 16:42 ` [OSS-Tools] [PATCH dt-utils 10/14] state: fix typos found with codespell Marco Felsch 2022-10-14 16:42 ` [OSS-Tools] [PATCH dt-utils 11/14] common: xstrdup: don't panic on xstrdup(NULL) Marco Felsch 2022-10-14 16:42 ` [OSS-Tools] [PATCH dt-utils 12/14] libdt: add of_property_write_strings support Marco Felsch 2022-10-14 16:42 ` [OSS-Tools] [PATCH dt-utils 13/14] libdt: add partition search function Marco Felsch 2022-10-14 16:42 ` [OSS-Tools] [PATCH dt-utils 14/14] state: sync with barebox to support new backend type Marco Felsch 2022-10-21 7:37 ` [OSS-Tools] [PATCH dt-utils 00/14] Sync Barebox-State code base Marco Felsch
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=20221014164204.3812506-4-m.felsch@pengutronix.de \ --to=m.felsch@pengutronix.de \ --cc=mfe@pengutronix.de \ --cc=oss-tools@pengutronix.de \ --subject='Re: [OSS-Tools] [PATCH dt-utils 03/14] state: backend_storage: deal gracefully with runtime bucket corruption' \ /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
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox