| Message ID | 1439809382-32419-1-git-send-email-jthumshirn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Johannes Thumshirn wrote: > If the bf_get() call in lpfc_mbx_cmpl_rdp_page_a2() does succeeds, execution > continues normally and mp gets kfree()d. > > If the subsequent call to lpfc_sli_issue_mbox() fails execution jumps to the > error label where lpfc_mbuf_free() is called with mp->virt and mp->phys as > function arguments. This is the use after free. Following the use after free mp > gets kfree()d again which is a double free. A similar patch was posted by Colin Ian King on 2015-07-31 [1]. [1] http://marc.info/?l=linux-scsi&m=143835937206204&w=2 Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Sebastian Herbszt <herbszt@gmx.de> writes: > Johannes Thumshirn wrote: >> If the bf_get() call in lpfc_mbx_cmpl_rdp_page_a2() does succeeds, execution >> continues normally and mp gets kfree()d. >> >> If the subsequent call to lpfc_sli_issue_mbox() fails execution jumps to the >> error label where lpfc_mbuf_free() is called with mp->virt and mp->phys as >> function arguments. This is the use after free. Following the use after free mp >> gets kfree()d again which is a double free. > > A similar patch was posted by Colin Ian King on 2015-07-31 [1]. > > [1] http://marc.info/?l=linux-scsi&m=143835937206204&w=2 OK, Is it already in James' tree (haven't checked)? The problematic code was merged for 4.2-rc1 so if the fix (Collin's or mine I don't care) could go in while we're still in the rc phase, we could avoid all that stable circus. Thanks for digging this out. Byte, Johannes -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Johannes Thumshirn wrote: > Sebastian Herbszt <herbszt@gmx.de> writes: > > > Johannes Thumshirn wrote: > >> If the bf_get() call in lpfc_mbx_cmpl_rdp_page_a2() does succeeds, execution > >> continues normally and mp gets kfree()d. > >> > >> If the subsequent call to lpfc_sli_issue_mbox() fails execution jumps to the > >> error label where lpfc_mbuf_free() is called with mp->virt and mp->phys as > >> function arguments. This is the use after free. Following the use after free mp > >> gets kfree()d again which is a double free. > > > > A similar patch was posted by Colin Ian King on 2015-07-31 [1]. > > > > [1] http://marc.info/?l=linux-scsi&m=143835937206204&w=2 > > OK, > > Is it already in James' tree (haven't checked)? The problematic code was > merged for 4.2-rc1 so if the fix (Collin's or mine I don't care) could go > in while we're still in the rc phase, we could avoid all that stable > circus. > > Thanks for digging this out. > > Byte, > Johannes It is not yet in scsi.git. James S., Dick, which patch do you prefer? Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 8/18/2015 6:27 PM, Sebastian Herbszt wrote: > Johannes Thumshirn wrote: >> Sebastian Herbszt <herbszt@gmx.de> writes: >> >>> Johannes Thumshirn wrote: >>>> If the bf_get() call in lpfc_mbx_cmpl_rdp_page_a2() does succeeds, execution >>>> continues normally and mp gets kfree()d. >>>> >>>> If the subsequent call to lpfc_sli_issue_mbox() fails execution jumps to the >>>> error label where lpfc_mbuf_free() is called with mp->virt and mp->phys as >>>> function arguments. This is the use after free. Following the use after free mp >>>> gets kfree()d again which is a double free. >>> A similar patch was posted by Colin Ian King on 2015-07-31 [1]. >>> >>> [1] http://marc.info/?l=linux-scsi&m=143835937206204&w=2 >> OK, >> >> Is it already in James' tree (haven't checked)? The problematic code was >> merged for 4.2-rc1 so if the fix (Collin's or mine I don't care) could go >> in while we're still in the rc phase, we could avoid all that stable >> circus. >> >> Thanks for digging this out. >> >> Byte, >> Johannes > It is not yet in scsi.git. > > James S., Dick, which patch do you prefer? > > Sebastian I looked at both and liked Johannes patch better. -- james s -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/scsi/lpfc/lpfc_mbox.c b/drivers/scsi/lpfc/lpfc_mbox.c index eb62772..4abb93a 100644 --- a/drivers/scsi/lpfc/lpfc_mbox.c +++ b/drivers/scsi/lpfc/lpfc_mbox.c @@ -2284,7 +2284,7 @@ lpfc_mbx_cmpl_rdp_page_a2(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox) (struct lpfc_rdp_context *)(mbox->context2); if (bf_get(lpfc_mqe_status, &mbox->u.mqe)) - goto error; + goto error_mbuf_free; lpfc_sli_bemem_bcopy(mp->virt, &rdp_context->page_a2, DMP_SFF_PAGE_A2_SIZE); @@ -2299,13 +2299,14 @@ lpfc_mbx_cmpl_rdp_page_a2(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox) mbox->mbox_cmpl = lpfc_mbx_cmpl_rdp_link_stat; mbox->context2 = (struct lpfc_rdp_context *) rdp_context; if (lpfc_sli_issue_mbox(phba, mbox, MBX_NOWAIT) == MBX_NOT_FINISHED) - goto error; + goto error_cmd_free; return; -error: +error_mbuf_free: lpfc_mbuf_free(phba, mp->virt, mp->phys); kfree(mp); +error_cmd_free: lpfc_sli4_mbox_cmd_free(phba, mbox); rdp_context->cmpl(phba, rdp_context, FAILURE); }
If the bf_get() call in lpfc_mbx_cmpl_rdp_page_a2() does succeeds, execution continues normally and mp gets kfree()d. If the subsequent call to lpfc_sli_issue_mbox() fails execution jumps to the error label where lpfc_mbuf_free() is called with mp->virt and mp->phys as function arguments. This is the use after free. Following the use after free mp gets kfree()d again which is a double free. Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> --- drivers/scsi/lpfc/lpfc_mbox.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)