From: Eric Sandeen Date: Tue, 30 Oct 2018 21:51:55 +0000 (-0500) Subject: xfs_repair: initialize realloced bplist in longform_dir2_entry_check X-Git-Tag: v4.19.0-rc1~8 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1624c340a53012b4afd1194d990890c140e3fb66;p=thirdparty%2Fxfsprogs-dev.git xfs_repair: initialize realloced bplist in longform_dir2_entry_check If we need to realloc the bplist[] array holding buffers for a given directory, we don't initialize the new slots. This causes a problem if the directory has holes, because those slots never get filled in. At the end of the function we call libxfs_putbuf for every non-null slot, and any uninitialized slots are segfault landmines. Make sure we initialize all new slots to NULL for this reason. Reported-by: Oleg Davydov Signed-off-by: Eric Sandeen Reviewed-by: Darrick J. Wong Signed-off-by: Eric Sandeen --- diff --git a/repair/phase6.c b/repair/phase6.c index e01732695..dc1cf8b9d 100644 --- a/repair/phase6.c +++ b/repair/phase6.c @@ -2335,6 +2335,8 @@ longform_dir2_entry_check(xfs_mount_t *mp, db = xfs_dir2_da_to_db(mp->m_dir_geo, da_bno); if (db >= num_bps) { + int last_size = num_bps; + /* more data blocks than expected */ num_bps = db + 1; bplist = realloc(bplist, num_bps * sizeof(struct xfs_buf*)); @@ -2342,6 +2344,9 @@ longform_dir2_entry_check(xfs_mount_t *mp, do_error(_("realloc failed in %s (%zu bytes)\n"), __func__, num_bps * sizeof(struct xfs_buf*)); + /* Initialize the new elements */ + for (i = last_size; i < num_bps; i++) + bplist[i] = NULL; } if (isblock)