tcp: Fix shift-out-of-bounds in dctcp_update_alpha().
In the Linux kernel, the following vulnerability has been resolved: tcp: Fix shift-out-of-bounds in dctcp_update_alpha(). In dctcp_update_alpha(), we use a module parameter dctcp_shift_g as follows: alpha -= min_not_zero(alpha, alpha >> dctcp_shift_g); ... delivered_ce <<= (10 - dctcp_shift_g); It seems syzkaller started fuzzing module parameters and triggered shift-out-of-bounds [0] by setting 100 to dctcp_shift_g: memcpy((void*)0x20000080, "/sys/module/tcp_dctcp/parameters/dctcp_shift_g\000", 47); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000080ul, /*flags=*/2ul, /*mode=*/0ul); memcpy((void*)0x20000000, "100\000", 4); syscall(__NR_write, /*fd=*/r[0], /*val=*/0x20000000ul, /*len=*/4ul); Let's limit the max value of dctcp_shift_g by param_set_uint_minmax(). With this patch: # echo 10 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g # cat /sys/module/tcp_dctcp/parameters/dctcp_shift_g 10 # echo 11 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g -bash: echo: write error: Invalid argument [0]: UBSAN: shift-out-of-bounds in net/ipv4/tcp_dctcp.c:143:12 shift exponent 100 is too large for 32-bit type 'u32' (aka 'unsigned int') CPU: 0 PID: 8083 Comm: syz-executor345 Not tainted 6.9.0-05151-g1b294a1f3561 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x201/0x300 lib/dump_stack.c:114 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_shift_o
CVE-2024-37356
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2024-37356
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "e3118e8359bb7c59555aca60c725106e6d78c5ce",
"lessThan": "06d0fe049b51b0a92a70df8333fd85c4ba3eb2c6",
"versionType": "git"
},
{
"status": "affected",
"version": "e3118e8359bb7c59555aca60c725106e6d78c5ce",
"lessThan": "6aacaa80d962f4916ccf90e2080306cec6c90fcf",
"versionType": "git"
},
{
"status": "affected",
"version": "e3118e8359bb7c59555aca60c725106e6d78c5ce",
"lessThan": "e9b2f60636d18dfd0dd4965b3316f88dfd6a2b31",
"versionType": "git"
},
{
"status": "affected",
"version": "e3118e8359bb7c59555aca60c725106e6d78c5ce",
"lessThan": "8602150286a2a860a1dc55cbd04f99316f19b40a",
"versionType": "git"
},
{
"status": "affected",
"version": "e3118e8359bb7c59555aca60c725106e6d78c5ce",
"lessThan": "e65d13ec00a738fa7661925fd5929ab3c765d4be",
"versionType": "git"
},
{
"status": "affected",
"version": "e3118e8359bb7c59555aca60c725106e6d78c5ce",
"lessThan": "02261d3f9dc7d1d7be7d778f839e3404ab99034c",
"versionType": "git"
},
{
"status": "affected",
"version": "e3118e8359bb7c59555aca60c725106e6d78c5ce",
"lessThan": "237340dee373b97833a491d2e99fcf1d4a9adafd",
"versionType": "git"
},
{
"status": "affected",
"version": "e3118e8359bb7c59555aca60c725106e6d78c5ce",
"lessThan": "3ebc46ca8675de6378e3f8f40768e180bb8afa66",
"versionType": "git"
}
],
"programFiles": [
"net/ipv4/tcp_dctcp.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "4.19.316",
"versionType": "semver",
"lessThanOrEqual": "4.19.*"
},
{
"status": "unaffected",
"version": "5.4.278",
"versionType": "semver",
"lessThanOrEqual": "5.4.*"
},
{
"status": "unaffected",
"version": "5.10.219",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.161",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.93",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.33",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.9.4",
"versionType": "semver",
"lessThanOrEqual": "6.9.*"
},
{
"status": "unaffected",
"version": "6.10",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ipv4/tcp_dctcp.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2024-37356
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #26602 · Revision 1
- Added to Heist Feed
- Publisher date