From 5d3805af279c93ef49a64701f35254676d709622 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 13 Jan 2020 16:23:46 +0300 Subject: [PATCH] ubi: Fix an error pointer dereference in error handling code If "seen_pebs = init_seen(ubi);" fails then "seen_pebs" is an error pointer and we try to kfree() it which results in an Oops. This patch re-arranges the error handling so now it only frees things which have been allocated successfully. Fixes: daef3dd1f0ae ("UBI: Fastmap: Add self check to detect absent PEBs") Signed-off-by: Dan Carpenter Signed-off-by: Richard Weinberger --- drivers/mtd/ubi/fastmap.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c index ac78e7a0e06a..53f448e7433a 100644 --- a/drivers/mtd/ubi/fastmap.c +++ b/drivers/mtd/ubi/fastmap.c @@ -1137,7 +1137,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, struct rb_node *tmp_rb; int ret, i, j, free_peb_count, used_peb_count, vol_count; int scrub_peb_count, erase_peb_count; - unsigned long *seen_pebs = NULL; + unsigned long *seen_pebs; fm_raw = ubi->fm_buf; memset(ubi->fm_buf, 0, ubi->fm_size); @@ -1151,7 +1151,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID); if (!dvbuf) { ret = -ENOMEM; - goto out_kfree; + goto out_free_avbuf; } avhdr = ubi_get_vid_hdr(avbuf); @@ -1160,7 +1160,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, seen_pebs = init_seen(ubi); if (IS_ERR(seen_pebs)) { ret = PTR_ERR(seen_pebs); - goto out_kfree; + goto out_free_dvbuf; } spin_lock(&ubi->volumes_lock); @@ -1328,7 +1328,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf); if (ret) { ubi_err(ubi, "unable to write vid_hdr to fastmap SB!"); - goto out_kfree; + goto out_free_seen; } for (i = 0; i < new_fm->used_blocks; i++) { @@ -1350,7 +1350,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, if (ret) { ubi_err(ubi, "unable to write vid_hdr to PEB %i!", new_fm->e[i]->pnum); - goto out_kfree; + goto out_free_seen; } } @@ -1360,7 +1360,7 @@ static int ubi_write_fastmap(struct ubi_device *ubi, if (ret) { ubi_err(ubi, "unable to write fastmap to PEB %i!", new_fm->e[i]->pnum); - goto out_kfree; + goto out_free_seen; } } @@ -1370,10 +1370,13 @@ static int ubi_write_fastmap(struct ubi_device *ubi, ret = self_check_seen(ubi, seen_pebs); dbg_bld("fastmap written!"); -out_kfree: - ubi_free_vid_buf(avbuf); - ubi_free_vid_buf(dvbuf); +out_free_seen: free_seen(seen_pebs); +out_free_dvbuf: + ubi_free_vid_buf(dvbuf); +out_free_avbuf: + ubi_free_vid_buf(avbuf); + out: return ret; }