From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jia-Ju Bai , =?UTF-8?q?Javier=20Gonz=C3=A1lez?= , =?UTF-8?q?Matias=20Bj=C3=B8rling?= , Jens Axboe , Sasha Levin Subject: [PATCH 4.19 061/361] lightnvm: pblk: fix two sleep-in-atomic-context bugs Date: Sun, 11 Nov 2018 14:16:48 -0800 Message-Id: <20181111221628.496312533@linuxfoundation.org> In-Reply-To: <20181111221619.915519183@linuxfoundation.org> References: <20181111221619.915519183@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jia-Ju Bai [ Upstream commit 7325b4bbe5952e3e939f15de812f2ee0c0d33ca9 ] The driver may sleep with holding a spinlock. The function call paths (from bottom to top) in Linux-4.16 are: [FUNC] nvm_dev_dma_alloc(GFP_KERNEL) drivers/lightnvm/pblk-core.c, 754: nvm_dev_dma_alloc in pblk_line_submit_smeta_io drivers/lightnvm/pblk-core.c, 1048: pblk_line_submit_smeta_io in pblk_line_init_bb drivers/lightnvm/pblk-core.c, 1434: pblk_line_init_bb in pblk_line_replace_data drivers/lightnvm/pblk-recovery.c, 980: pblk_line_replace_data in pblk_recov_l2p drivers/lightnvm/pblk-recovery.c, 976: spin_lock in pblk_recov_l2p [FUNC] bio_map_kern(GFP_KERNEL) drivers/lightnvm/pblk-core.c, 762: bio_map_kern in pblk_line_submit_smeta_io drivers/lightnvm/pblk-core.c, 1048: pblk_line_submit_smeta_io in pblk_line_init_bb drivers/lightnvm/pblk-core.c, 1434: pblk_line_init_bb in pblk_line_replace_data drivers/lightnvm/pblk-recovery.c, 980: pblk_line_replace_data in pblk_recov_l2p drivers/lightnvm/pblk-recovery.c, 976: spin_lock in pblk_recov_l2p To fix these bugs, the call to pblk_line_replace_data() is moved out of the spinlock protection. These bugs are found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/lightnvm/pblk-recovery.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/lightnvm/pblk-recovery.c +++ b/drivers/lightnvm/pblk-recovery.c @@ -956,12 +956,14 @@ next: } } - spin_lock(&l_mg->free_lock); if (!open_lines) { + spin_lock(&l_mg->free_lock); WARN_ON_ONCE(!test_and_clear_bit(meta_line, &l_mg->meta_bitmap)); + spin_unlock(&l_mg->free_lock); pblk_line_replace_data(pblk); } else { + spin_lock(&l_mg->free_lock); /* Allocate next line for preparation */ l_mg->data_next = pblk_line_get(pblk); if (l_mg->data_next) { @@ -969,8 +971,8 @@ next: l_mg->data_next->type = PBLK_LINETYPE_DATA; is_next = 1; } + spin_unlock(&l_mg->free_lock); } - spin_unlock(&l_mg->free_lock); if (is_next) pblk_line_erase(pblk, l_mg->data_next);