The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.14.y git checkout FETCH_HEAD git cherry-pick -x c8e22b7a1694bb8d025ea636816472739d859145 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023041705-wages-cabbage-66be@gregkh' --subject-prefix 'PATCH 4.14.y' HEAD^.. Possible dependencies: c8e22b7a1694 ("scsi: ses: Handle enclosure with just a primary component gracefully") 3fe97ff3d949 ("scsi: ses: Don't attach if enclosure has no components") 6396bb221514 ("treewide: kzalloc() -> kcalloc()") 5f85942c2ea2 ("Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From c8e22b7a1694bb8d025ea636816472739d859145 Mon Sep 17 00:00:00 2001 From: Jiri Kosina <jkosina@xxxxxxx> Date: Tue, 4 Apr 2023 21:23:42 +0200 Subject: [PATCH] scsi: ses: Handle enclosure with just a primary component gracefully This reverts commit 3fe97ff3d949 ("scsi: ses: Don't attach if enclosure has no components") and introduces proper handling of case where there are no detected secondary components, but primary component (enumerated in num_enclosures) does exist. That fix was originally proposed by Ding Hui <dinghui@xxxxxxxxxxxxxx>. Completely ignoring devices that have one primary enclosure and no secondary one results in ses_intf_add() bailing completely scsi 2:0:0:254: enclosure has no enumerated components scsi 2:0:0:254: Failed to bind enclosure -12ven in valid configurations such even on valid configurations with 1 primary and 0 secondary enclosures as below: # sg_ses /dev/sg0 3PARdata SES 3321 Supported diagnostic pages: Supported Diagnostic Pages [sdp] [0x0] Configuration (SES) [cf] [0x1] Short Enclosure Status (SES) [ses] [0x8] # sg_ses -p cf /dev/sg0 3PARdata SES 3321 Configuration diagnostic page: number of secondary subenclosures: 0 generation code: 0x0 enclosure descriptor list Subenclosure identifier: 0 [primary] relative ES process id: 0, number of ES processes: 1 number of type descriptor headers: 1 enclosure logical identifier (hex): 20000002ac02068d enclosure vendor: 3PARdata product: VV rev: 3321 type descriptor header and text list Element type: Unspecified, subenclosure id: 0 number of possible elements: 1 The changelog for the original fix follows ===== We can get a crash when disconnecting the iSCSI session, the call trace like this: [ffff00002a00fb70] kfree at ffff00000830e224 [ffff00002a00fba0] ses_intf_remove at ffff000001f200e4 [ffff00002a00fbd0] device_del at ffff0000086b6a98 [ffff00002a00fc50] device_unregister at ffff0000086b6d58 [ffff00002a00fc70] __scsi_remove_device at ffff00000870608c [ffff00002a00fca0] scsi_remove_device at ffff000008706134 [ffff00002a00fcc0] __scsi_remove_target at ffff0000087062e4 [ffff00002a00fd10] scsi_remove_target at ffff0000087064c0 [ffff00002a00fd70] __iscsi_unbind_session at ffff000001c872c4 [ffff00002a00fdb0] process_one_work at ffff00000810f35c [ffff00002a00fe00] worker_thread at ffff00000810f648 [ffff00002a00fe70] kthread at ffff000008116e98 In ses_intf_add, components count could be 0, and kcalloc 0 size scomp, but not saved in edev->component[i].scratch In this situation, edev->component[0].scratch is an invalid pointer, when kfree it in ses_intf_remove_enclosure, a crash like above would happen The call trace also could be other random cases when kfree cannot catch the invalid pointer We should not use edev->component[] array when the components count is 0 We also need check index when use edev->component[] array in ses_enclosure_data_process ===== Reported-by: Michal Kolar <mich.k@xxxxxxxxx> Originally-by: Ding Hui <dinghui@xxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Fixes: 3fe97ff3d949 ("scsi: ses: Don't attach if enclosure has no components") Signed-off-by: Jiri Kosina <jkosina@xxxxxxx> Link: https://lore.kernel.org/r/nycvar.YFH.7.76.2304042122270.29760@xxxxxxxxxxxxx Tested-by: Michal Kolar <mich.k@xxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c index b11a9162e73a..b54f2c6c08c3 100644 --- a/drivers/scsi/ses.c +++ b/drivers/scsi/ses.c @@ -509,9 +509,6 @@ static int ses_enclosure_find_by_addr(struct enclosure_device *edev, int i; struct ses_component *scomp; - if (!edev->component[0].scratch) - return 0; - for (i = 0; i < edev->components; i++) { scomp = edev->component[i].scratch; if (scomp->addr != efd->addr) @@ -602,8 +599,10 @@ static void ses_enclosure_data_process(struct enclosure_device *edev, components++, type_ptr[0], name); - else + else if (components < edev->components) ecomp = &edev->component[components++]; + else + ecomp = ERR_PTR(-EINVAL); if (!IS_ERR(ecomp)) { if (addl_desc_ptr) { @@ -734,11 +733,6 @@ static int ses_intf_add(struct device *cdev, components += type_ptr[1]; } - if (components == 0) { - sdev_printk(KERN_WARNING, sdev, "enclosure has no enumerated components\n"); - goto err_free; - } - ses_dev->page1 = buf; ses_dev->page1_len = len; buf = NULL; @@ -780,9 +774,11 @@ static int ses_intf_add(struct device *cdev, buf = NULL; } page2_not_supported: - scomp = kcalloc(components, sizeof(struct ses_component), GFP_KERNEL); - if (!scomp) - goto err_free; + if (components > 0) { + scomp = kcalloc(components, sizeof(struct ses_component), GFP_KERNEL); + if (!scomp) + goto err_free; + } edev = enclosure_register(cdev->parent, dev_name(&sdev->sdev_gendev), components, &ses_enclosure_callbacks);
