Messages in this thread | | | From | Oleksandr Natalenko <> | Subject | [PATCH 0/3] scsi: qedf: sanitise uaccess | Date | Fri, 28 Jul 2023 08:58:16 +0200 |
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qedf driver, debugfs part of it specifically, touches __user pointers directly for printing out info to userspace via sprintf(), which may cause crash like this:
BUG: unable to handle kernel paging request at 00007ffd1d6b43a0 IP: [<ffffffffaa7a882a>] string.isra.7+0x6a/0xf0 Oops: 0003 [#1] SMP Call Trace: [<ffffffffaa7a9f31>] vsnprintf+0x201/0x6a0 [<ffffffffaa7aa556>] sprintf+0x56/0x80 [<ffffffffc04227ed>] qedf_dbg_stop_io_on_error_cmd_read+0x6d/0x90 [qedf] [<ffffffffaa65bb2f>] vfs_read+0x9f/0x170 [<ffffffffaa65cb82>] SyS_pread64+0x92/0xc0
Avoid this by preparing the info in a kernel buffer first, either allocated on stack for small printouts, or via vmalloc() for big ones, and then copying it to the userspace properly.
Previous submission is an RFC: [1]. There are no code changes since then. The RFC prefix is dropped. The Tested-by tag from Laurence is added.
There's similar submission from Saurav [2], but we agreed I could nack it and proceed with my one.
[1] https://lore.kernel.org/linux-scsi/20230724120241.40495-1-oleksandr@redhat.com/ [2] https://lore.kernel.org/linux-scsi/20230726101236.11922-1-skashyap@marvell.com/
Oleksandr Natalenko (3): scsi: qedf: do not touch __user pointer in qedf_dbg_stop_io_on_error_cmd_read() directly scsi: qedf: do not touch __user pointer in qedf_dbg_debug_cmd_read() directly scsi: qedf: do not touch __user pointer in qedf_dbg_fp_int_cmd_read() directly
drivers/scsi/qedf/qedf_dbg.h | 2 ++ drivers/scsi/qedf/qedf_debugfs.c | 35 +++++++++++++++++++------------- 2 files changed, 23 insertions(+), 14 deletions(-)
-- 2.41.0
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