f6fadff33e
While hacking on kTLS, I ran into the following panic from an unprivileged netserver / netperf TCP session: BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 PGD 800000037f378067 P4D 800000037f378067 PUD 3c0e61067 PMD 0 Oops: 0010 [#1] SMP KASAN PTI CPU: 1 PID: 2289 Comm: netserver Not tainted 4.17.0+ #139 Hardware name: LENOVO 20FBCTO1WW/20FBCTO1WW, BIOS N1FET47W (1.21 ) 11/28/2016 RIP: 0010: (null) Code: Bad RIP value. RSP: 0018:ffff88036abcf740 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88036f5f6800 RCX: 1ffff1006debed26 RDX: ffff88036abcf920 RSI: ffff8803cb1a4f00 RDI: ffff8803c258c280 RBP: ffff8803c258c280 R08: ffff8803c258c280 R09: ffffed006f559d48 R10: ffff88037aacea43 R11: ffffed006f559d49 R12: ffff8803c258c280 R13: ffff8803cb1a4f20 R14: 00000000000000db R15: ffffffffc168a350 FS: 00007f7e631f4700(0000) GS:ffff8803d1c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000003ccf64005 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? tls_sw_poll+0xa4/0x160 [tls] ? sock_poll+0x20a/0x680 ? do_select+0x77b/0x11a0 ? poll_schedule_timeout.constprop.12+0x130/0x130 ? pick_link+0xb00/0xb00 ? read_word_at_a_time+0x13/0x20 ? vfs_poll+0x270/0x270 ? deref_stack_reg+0xad/0xe0 ? __read_once_size_nocheck.constprop.6+0x10/0x10 [...] Debugging further, it turns out that calling into ctx->sk_poll() is invalid since sk_poll itself is NULL which was saved from the original TCP socket in order for tls_sw_poll() to invoke it. Looks like the recent conversion from poll to poll_mask callback started in |
||
---|---|---|
Documentation | ||
LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
README
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.