From: Bart Van Assche Date: Wed, 18 Nov 2015 22:56:36 +0000 (-0800) Subject: Fix a memory leak in scsi_host_dev_release() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b49493f99690c8eaacfbc635bafaad629ea2c036;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git Fix a memory leak in scsi_host_dev_release() Avoid that kmemleak reports the following memory leak if a SCSI LLD calls scsi_host_alloc() and scsi_host_put() but neither scsi_host_add() nor scsi_host_remove(). The following shell command triggers that scenario: for ((i=0; i<2; i++)); do srp_daemon -oac | while read line; do echo $line >/sys/class/infiniband_srp/srp-mlx4_0-1/add_target done done unreferenced object 0xffff88021b24a220 (size 8): comm "srp_daemon", pid 56421, jiffies 4295006762 (age 4240.750s) hex dump (first 8 bytes): 68 6f 73 74 35 38 00 a5 host58.. backtrace: [] kmemleak_alloc+0x7a/0xc0 [] __kmalloc_track_caller+0xfe/0x160 [] kvasprintf+0x5b/0x90 [] kvasprintf_const+0x8d/0xb0 [] kobject_set_name_vargs+0x3c/0xa0 [] dev_set_name+0x3c/0x40 [] scsi_host_alloc+0x327/0x4b0 [] srp_create_target+0x4e/0x8a0 [ib_srp] [] dev_attr_store+0x1b/0x20 [] sysfs_kf_write+0x4a/0x60 [] kernfs_fop_write+0x14e/0x180 [] __vfs_write+0x2f/0xf0 [] vfs_write+0xa4/0x100 [] SyS_write+0x54/0xc0 [] entry_SYSCALL_64_fastpath+0x12/0x6f Signed-off-by: Bart Van Assche Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Sagi Grimberg Reviewed-by: Lee Duncan Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: stable Signed-off-by: Martin K. Petersen --- diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 8bb173e01084..7d647a32f85e 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -326,6 +326,17 @@ static void scsi_host_dev_release(struct device *dev) kfree(queuedata); } + if (shost->shost_state == SHOST_CREATED) { + /* + * Free the shost_dev device name here if scsi_host_alloc() + * and scsi_host_put() have been called but neither + * scsi_host_add() nor scsi_host_remove() has been called. + * This avoids that the memory allocated for the shost_dev + * name is leaked. + */ + kfree(dev_name(&shost->shost_dev)); + } + scsi_destroy_command_freelist(shost); if (shost_use_blk_mq(shost)) { if (shost->tag_set.tags)