| From | Greg Kroah-Hartman <> | Subject | [ 134/187] dm persistent data: handle space map checker creation failure | Date | Thu, 12 Jul 2012 15:34:50 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mike Snitzer <snitzer@redhat.com>
commit 62662303e7f590fdfbb0070ab820a0ad4267c119 upstream.
If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and dm_sm_checker_create() fails, dm_tm_create_internal() would still return success even though it cleaned up all resources it was supposed to have created. This will lead to a kernel crash:
general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC ... RIP: 0010:[<ffffffff81593659>] [<ffffffff81593659>] dm_bufio_get_block_size+0x9/0x20 Call Trace: [<ffffffff81599bae>] dm_bm_block_size+0xe/0x10 [<ffffffff8159b8b8>] sm_ll_init+0x78/0xd0 [<ffffffff8159c1a6>] sm_ll_new_disk+0x16/0xa0 [<ffffffff8159c98e>] dm_sm_disk_create+0xfe/0x160 [<ffffffff815abf6e>] dm_pool_metadata_open+0x16e/0x6a0 [<ffffffff815aa010>] pool_ctr+0x3f0/0x900 [<ffffffff8158d565>] dm_table_add_target+0x195/0x450 [<ffffffff815904c4>] table_load+0xe4/0x330 [<ffffffff815917ea>] ctl_ioctl+0x15a/0x2c0 [<ffffffff81591963>] dm_ctl_ioctl+0x13/0x20 [<ffffffff8116a4f8>] do_vfs_ioctl+0x98/0x560 [<ffffffff8116aa51>] sys_ioctl+0x91/0xa0 [<ffffffff81869f52>] system_call_fastpath+0x16/0x1b
Fix the space map checker code to return an appropriate ERR_PTR and have dm_sm_disk_create() and dm_tm_create_internal() check for it with IS_ERR.
Reported-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/persistent-data/dm-space-map-checker.c | 24 ++++++++++---------- drivers/md/persistent-data/dm-space-map-disk.c | 11 ++++++++- drivers/md/persistent-data/dm-transaction-manager.c | 8 +++++- 3 files changed, 28 insertions(+), 15 deletions(-)
--- a/drivers/md/persistent-data/dm-space-map-checker.c +++ b/drivers/md/persistent-data/dm-space-map-checker.c @@ -343,25 +343,25 @@ struct dm_space_map *dm_sm_checker_creat int r; struct sm_checker *smc; - if (!sm) - return NULL; + if (IS_ERR_OR_NULL(sm)) + return ERR_PTR(-EINVAL); smc = kmalloc(sizeof(*smc), GFP_KERNEL); if (!smc) - return NULL; + return ERR_PTR(-ENOMEM); memcpy(&smc->sm, &ops_, sizeof(smc->sm)); r = ca_create(&smc->old_counts, sm); if (r) { kfree(smc); - return NULL; + return ERR_PTR(r); } r = ca_create(&smc->counts, sm); if (r) { ca_destroy(&smc->old_counts); kfree(smc); - return NULL; + return ERR_PTR(r); } smc->real_sm = sm; @@ -371,7 +371,7 @@ struct dm_space_map *dm_sm_checker_creat ca_destroy(&smc->counts); ca_destroy(&smc->old_counts); kfree(smc); - return NULL; + return ERR_PTR(r); } r = ca_commit(&smc->old_counts, &smc->counts); @@ -379,7 +379,7 @@ struct dm_space_map *dm_sm_checker_creat ca_destroy(&smc->counts); ca_destroy(&smc->old_counts); kfree(smc); - return NULL; + return ERR_PTR(r); } return &smc->sm; @@ -391,25 +391,25 @@ struct dm_space_map *dm_sm_checker_creat int r; struct sm_checker *smc; - if (!sm) - return NULL; + if (IS_ERR_OR_NULL(sm)) + return ERR_PTR(-EINVAL); smc = kmalloc(sizeof(*smc), GFP_KERNEL); if (!smc) - return NULL; + return ERR_PTR(-ENOMEM); memcpy(&smc->sm, &ops_, sizeof(smc->sm)); r = ca_create(&smc->old_counts, sm); if (r) { kfree(smc); - return NULL; + return ERR_PTR(r); } r = ca_create(&smc->counts, sm); if (r) { ca_destroy(&smc->old_counts); kfree(smc); - return NULL; + return ERR_PTR(r); } smc->real_sm = sm; --- a/drivers/md/persistent-data/dm-space-map-disk.c +++ b/drivers/md/persistent-data/dm-space-map-disk.c @@ -290,7 +290,16 @@ struct dm_space_map *dm_sm_disk_create(s dm_block_t nr_blocks) { struct dm_space_map *sm = dm_sm_disk_create_real(tm, nr_blocks); - return dm_sm_checker_create_fresh(sm); + struct dm_space_map *smc; + + if (IS_ERR_OR_NULL(sm)) + return sm; + + smc = dm_sm_checker_create_fresh(sm); + if (IS_ERR(smc)) + dm_sm_destroy(sm); + + return smc; } EXPORT_SYMBOL_GPL(dm_sm_disk_create); --- a/drivers/md/persistent-data/dm-transaction-manager.c +++ b/drivers/md/persistent-data/dm-transaction-manager.c @@ -345,8 +345,10 @@ static int dm_tm_create_internal(struct } *sm = dm_sm_checker_create(inner); - if (!*sm) + if (IS_ERR(*sm)) { + r = PTR_ERR(*sm); goto bad2; + } } else { r = dm_bm_write_lock(dm_tm_get_bm(*tm), sb_location, @@ -365,8 +367,10 @@ static int dm_tm_create_internal(struct } *sm = dm_sm_checker_create(inner); - if (!*sm) + if (IS_ERR(*sm)) { + r = PTR_ERR(*sm); goto bad2; + } } return 0;
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