ubifs: fix crash building without decompressors

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()!
  BUG!
  [<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
compr_init.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20220713092047.1588210-1-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

0 files changed, 0 insertions, 0 deletions