mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Ahmad Fatoum <>
Cc: Ahmad Fatoum <>
Subject: [PATCH master] ubifs: fix crash building without decompressors
Date: Wed, 13 Jul 2022 11:20:47 +0200	[thread overview]
Message-ID: <> (raw)

When building barebox with ubifs support, but without decompressors
enabled, we run into a NULL pointer dereference:

  BUG: failure at lib/string.c:249/strncmp()!
  [<4fd8ea59>] (unwind_backtrace+0x1/0x78) from [<4fd014e5>] (panic+0x1d/0x34)
  [<4fd014e5>] (panic+0x1d/0x34) from [<4fd65ed1>] (strncmp+0x2d/0x50)
  [<4fd65ed1>] (strncmp+0x2d/0x50) from [<4fd784bb>] (compr_init+0x4b/0x70)
  [<4fd784bb>] (compr_init+0x4b/0x70) from [<4fd78915>] (ubifs_compressors_init+0x15/0x40)
  [<4fd78915>] (ubifs_compressors_init+0x15/0x40) from [<4fd78e89>] (ubifs_init+0x2d/0x48)
  [<4fd78e89>] (ubifs_init+0x2d/0x48) from [<4fd01159>] (start_barebox+0x35/0x6c)
  [<4fd01159>] (start_barebox+0x35/0x6c) from [<4fd8c9f3>] (barebox_non_pbl_start+0x127/0x170)
  [<4fd8c9f3>] (barebox_non_pbl_start+0x127/0x170) from [<4fd00005>] (__bare_init_start+0x1/0xc)

This is because the loop in crypto_alloc_comp iterates over all possible
decompressors and then accesses comp->capi_name, which will be NULL for
unusable decompressors. Add a NULL check to handle this gracefully.
A check for alg_name isn't needed because it's already checked in

Signed-off-by: Ahmad Fatoum <>
 fs/ubifs/ubifs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ubifs/ubifs.c b/fs/ubifs/ubifs.c
index e7b434c1960e..0b4f3de773e7 100644
--- a/fs/ubifs/ubifs.c
+++ b/fs/ubifs/ubifs.c
@@ -125,7 +125,8 @@ static inline struct crypto_comp
-		if (strncmp(alg_name, comp->capi_name, strlen(alg_name)) == 0) {
+		if (comp->capi_name &&
+		    strncmp(alg_name, comp->capi_name, strlen(alg_name)) == 0) {
 			ptr->compressor = i;
 			return ptr;

             reply	other threads:[~2022-07-13  9:22 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-13  9:20 Ahmad Fatoum [this message]
2022-07-14  8:08 ` Sascha Hauer

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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \
    --subject='Re: [PATCH master] ubifs: fix crash building without decompressors' \

* 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